Reference Tool — Not an Assessment

Developmental Language Disorder (DLD)

Australian practice context, 2026. An education and behaviour-practice reference — not a diagnostic tool. In Australia, speech pathologists assess and diagnose language disorders. Uses current Speech Pathology Australia information and the international CATALISE terminology framework, with current research on school, social-emotional and intervention outcomes.

What DLD is: a persistent developmental difficulty learning and using spoken language that creates functional problems and is not explained by a known differentiating biomedical condition. Speech Pathology Australia describes DLD as affecting about 7% of people — roughly 1 in 14.

Why schools miss it: a student may speak fluently, joke, argue and sound socially capable while still misunderstanding vocabulary, grammar, questions, instructions and implied meaning. Language failure can look like ignoring, refusal, lying, laziness, poor memory, impulsivity, rudeness, weak remorse or deliberate non-compliance — none of those behaviours proves DLD. Main practical rule: do not use verbal fluency as a proxy for comprehension.

Start with a language domain

Click the one closest to what you're seeing — each page covers what it is, what it can look like at school, and what helps.

More to explore

Behaviour traps, differentials, assessment, impact and the strategy toolkit.

Important: this handbook is designed to improve recognition, referral and school support. It does not diagnose DLD. A student with suspected language disorder requires assessment by an appropriately qualified speech pathologist, with other disciplines involved where the differential is complex.

ES tools that may help

ES tools that may help with the classroom patterns you selected. These products do not assess or treat the condition above. They provide practical classroom systems that may help with some of the behaviours, demands, communication needs or regulation patterns you are seeing. Language load, processing demands, and behaviour that can be mistaken for refusal or non-compliance.

Adult Language Scripts

A$100

Instructional Demand System

A$200

View system →

Behaviour Translation Guide

A$200

Currently available for Primary settings.

View system →

Receptive language

Understanding words, sentences, questions, conversations and implied meaning.

Reference tool — informs practice, does not diagnose or label.

iWhat it is

Following only part of an instruction: The rest wasn't processed, not ignored.
Answering a different question from the one asked: The question itself may not have been fully understood.
Copying peers to work out what to do: Using peers as an instruction decoder.
Agreeing despite not understanding: "Yes" can be a social response, not a comprehension check.
Missing qualifiers such as before/after/unless/except: These small words carry a lot of the meaning.
Understanding familiar routines better than new language: Routine masks the underlying difficulty.

!Common trap

Adults often overestimate receptive language because expressive speech sounds competent. A student can talk far better than they understand complex language.

✓What helps

Give one or two steps at a time; visually list the sequence rather than stacking instructions.
Pre-teach unfamiliar vocabulary with a model before using it in an instruction.
Name the object, person and location directly instead of relying on pronouns ("it", "he", "there").
Make sequence and conditions visible — show "before/after," "if/unless" rather than leaving them in speech only.
Pause after key information and allow real response time before repeating or escalating.
Swap "Do you understand?" for "What are you doing first?" or "Show me where you start."

Expressive language

Selecting words and constructing sentences and connected explanations.

Reference tool — informs practice, does not diagnose or label.

iWhat it is

Using vague words: "Thing", "stuff", "that one" — the specific word isn't available in the moment.
Long pauses or "I don't know": The idea is there but the words are not — retrieval is slow despite knowledge.
Short, immature or grammatically unusual sentences: Construction is harder than it looks in casual talk.
Losing the sequence when explaining an event: Organising connected language under pressure is demanding.
Difficulty explaining cause, motive or consequences: These require more complex language structures than simple recall.
Poor repair when the listener misunderstands: Repeating the same wording louder instead of explaining differently.

✓What helps

Wait rather than filling every silence — retrieval may just be slow.
Offer semantic or first-sound cues if appropriate when the word won't come.
Clarify without humiliation, and model the precise word rather than correcting bluntly.
Reduce audience pressure and return to the idea if the student gives up or jokes to avoid exposing the difficulty.
Use options initially (recognition), then build toward independent retrieval.

Vocabulary & semantics

Knowing a word is more than being able to name it.

Reference tool — informs practice, does not diagnose or label.

Language demand	Possible DLD difficulty	School consequence
Learning new vocabulary	Slower mapping of sound, meaning and use; weaker retention/generalisation.	Curriculum words accumulate faster than they are consolidated.
Depth of word knowledge	Knows a rough meaning but not category, attributes, multiple meanings or relationships.	Can appear to understand until questions require precision.
Word retrieval	Word is known but difficult to access quickly.	Pauses, substitutions, vague wording, frustration or giving up.
Multiple-meaning words	Difficulty selecting meaning from context.	Problems with jokes, curriculum terms and ambiguous instructions.
Relational language	Terms such as unless, despite, neither, between, before, except.	Errors can be mistaken for carelessness or rule-breaking.

✓What helps

Re-teach explicitly and revisit over time — hearing a word once does not mean it was encoded.
Teach meaning plus sound/word form together; use examples and retrieval practice.
Test use across sentences, subjects and situations — being able to define a word doesn't mean it generalises.
Use cues, visuals and planned retrieval rather than assuming a change in motivation when access is fragile.

Exposure alone may not be enough, and gains from explicit teaching may stay specific to the words actually taught — target selection matters.

Grammar, morphology & syntax

Often subtle in casual conversation, much more obvious when sentences become long, passive, embedded or abstract.

Reference tool — informs practice, does not diagnose or label.

Example	Hidden language load	Possible error
"Before you leave, give the sheet to Sam after you have highlighted the evidence."	Temporal clauses, pronouns, sequence, embedded action.	Student highlights later, gives wrong sheet, leaves first or does nothing.
"The boy who the teacher warned was waiting outside."	Relative clause and role assignment.	Misidentifies who was warned or who was waiting.
"If you finish the first section, you can choose either task, unless the teacher asks you to stay."	Conditional, alternatives, exception.	Student hears the preferred option but misses the condition.
"He was accused of taking it, but he denied that he had."	Reference, tense, abstract legal/social vocabulary.	Misunderstands who did what and whether the statement is fact or allegation.

✓What helps

Explicit teaching of sentence structures, often with visual/metalinguistic supports, has evidence for some school-age groups — no single programme fits every profile.
Rephrase with simpler syntax or show/model the meaning instead of repeating the same sentence louder.
Make sequence and conditions visible rather than leaving temporal/conditional language in speech alone.

Narrative & discourse

Telling what happened.

Reference tool — informs practice, does not diagnose or label.

Narrative demand	What can go wrong	How adults may misread it
Sequence events	Events omitted, reordered or linked poorly.	"The story keeps changing."
Provide enough context	Assumes listener knows people/places/events.	"He is being evasive."
Explain cause and effect	Can state events but not connect motives and consequences.	"He has no insight."
Use precise vocabulary	Vague references and word-finding gaps.	"He is making it up."
Answer follow-up questions	Question wording changes the response demand.	"He answered before, now he won't."
Retell under stress	Language access can worsen with arousal and social pressure.	"He knows exactly what he did and is refusing to explain."

!Incident interviews

An inconsistent or incomplete recount can reflect language and narrative limitations. It can also reflect avoidance, dishonesty, trauma, memory problems or other factors. DLD is a hypothesis to investigate, not an excuse to assume every inaccurate account is accidental.

✓What helps

Teach story/event structure, causal links and how much context a listener needs — though improvement in trained structures doesn't guarantee spontaneous generalisation.
Clarify one event at a time; use timeline/visual supports rather than open-ended "tell me everything."
Ask "tell me the two jobs in your own words" rather than "what did I just say" — checks meaning, not verbatim repetition.

Pragmatic language

Using language appropriately in context and reading conversational expectations.

Reference tool — informs practice, does not diagnose or label.

Skill	Possible difficulty	Real-world effect
Inference	Working out information that was implied but not directly stated.	Misses teacher intent, peer subtext, sarcasm or consequences that seem "obvious" to others.
Conversational relevance	Selecting the amount and type of information the listener needs.	Overtalks, undertalks, changes topic, appears self-focused.
Repair	Recognising and fixing a misunderstanding.	Repeats the same wording louder instead of explaining differently.
Perspective in language	Representing what another person knows, thinks or believes.	Weak conflict explanations and social problem-solving.
Figurative language	Idioms, jokes, metaphor, indirect requests.	Literal response or inappropriate reaction.

!Not automatically autism

Pragmatic difficulties occur in DLD, ADHD and other conditions. Autism requires the broader diagnostic pattern including restricted/repetitive behaviours or interests — pragmatic difficulty alone is not autism.

The basics

Foundations

Reference tool — informs practice, does not diagnose or label.

iDLD in one page: what it is and is not

Question	Practical answer
Is DLD a speech disorder?	No. Speech is how sounds are produced. Language is the system for understanding and expressing words, sentences and connected meaning. DLD can exist with clear speech.
Is DLD an intellectual disability?	No. DLD does not require a verbal/non-verbal IQ gap, and low non-verbal ability that does not meet criteria for intellectual disability does not automatically exclude DLD.
Is DLD caused by bad parenting or poor teaching?	No. DLD is a neurodevelopmental condition. Environment can affect language opportunity and outcomes, but parenting does not cause DLD.
Can DLD coexist with ADHD or dyslexia?	Yes. CATALISE explicitly allows co-occurring neurodevelopmental conditions such as ADHD, dyslexia and DCD.
Can an autistic student have language disorder?	Yes, but under CATALISE terminology the language difficulty is described as language disorder associated with autism rather than DLD.
Does fluent talking rule it out?	No. Vocabulary depth, sentence comprehension, narrative organisation, inference and processing can be weak despite lots of talking.
Is it lifelong?	Usually persistent. The profile changes as demands change, and effective support can substantially improve functioning.

Core idea: DLD is often hidden because the disability sits inside the language system used to explain, question, teach, correct and assess the student.

iTerminology: DLD, Language Disorder and old labels

Term	How to use it now	Important distinction
Language Disorder	Broad term for language difficulties that are persistent, functionally significant and likely to have a poor prognosis.	Can be used whether or not there is a known differentiating condition.
Developmental Language Disorder (DLD)	Preferred CATALISE term when the language disorder is not associated with a known differentiating biomedical condition.	Risk factors and conditions such as ADHD/dyslexia can co-occur and do not automatically exclude DLD.
Language disorder associated with X	Used when a differentiating condition such as autism, intellectual disability, brain injury, genetic syndrome or sensorineural hearing loss is present.	The language impairment remains real; the label simply identifies the broader condition.
Specific Language Impairment (SLI)	Older term still found in reports and research.	The word "specific" implied exclusions and IQ discrepancy rules that modern consensus rejected.
Receptive/expressive language disorder	Older/common descriptive wording.	Useful to describe profile, but DLD is not cleanly split into two fixed subtypes.
Language delay	Can be appropriate for younger children when prognosis is unclear.	Not every early delay persists into DLD.

iHow common is it — and why is it still missed?

Finding	What it means
About 7% / around 1 in 14	Speech Pathology Australia describes DLD as a common but hidden disorder. RCSLT reports 7.58% in school-aged children.
Australian Raine Study: 6.4% at age 10	In 1,626 Australian 10-year-olds with language data, 104 met the study criteria for DLD; profiles included expressive, receptive and mixed receptive-expressive difficulties.
Not mainly a boys condition	The Raine Study did not find a significant sex difference in its DLD subgroup.
Hidden rather than rare	Language problems can be concealed by social scripts, humour, copying, behaviour, simple sentences, familiar routines and adults unconsciously simplifying language.
Recognition often drops as speech becomes fluent	Older students may sound conversationally competent while curriculum, social and disciplinary language becomes increasingly abstract and inferential.

iSpeech, language, communication and literacy are not the same thing

System	What it includes	Possible difficulty
Speech	Producing speech sounds clearly and fluently.	Articulation/phonology, motor speech, fluency.
Receptive language	Understanding words, sentences, questions, conversations and implied meaning.	Missed instructions, literal interpretation, weak question comprehension.
Expressive language	Selecting words and constructing sentences and connected explanations.	Word finding, vague language, short/immature grammar, disorganised recounts.
Pragmatic/social communication	Using language appropriately in context and reading conversational expectations.	Turn-taking, relevance, inference, repairing misunderstandings.
Literacy	Using language through reading and writing.	Decoding can be intact while reading comprehension and written expression are weak.
Communication	The whole exchange — language, gesture, context, shared knowledge and interaction.	A student can have difficulty even when speech itself sounds normal.

Reading the behaviour: hidden language traps

Practical lens

Reference tool — informs practice, does not diagnose or label.

iLanguage load is not the same as task difficulty

Task	Low language version	High language version
Maths	37 + 28 = ?	"Sam had 37 cards and received 28 more. How many does he have altogether? Explain how you know."
Behaviour expectation	"Phone away now."	"You know the expectation around personal devices during independent learning time."
Transition	Visual timer + "Pack up. Bag. Door."	"Once everyone has finished, organise what you need for next period before making your way outside."
Reflection	Choose from concrete options about what happened.	"Explain how your choices affected the learning environment and what you could do differently next time."

Functional assessment point: if behaviour reliably rises when the language complexity rises, the antecedent may be language load rather than the surface activity itself.

iWord finding — "I know it but cannot say it"

What you may see	Possible mechanism	Useful response
Long pause	Retrieval is slow despite knowledge.	Wait rather than filling every silence.
"Thing / stuff / that one"	Specific word unavailable.	Offer semantic or first-sound cues if appropriate.
Wrong related word	Target meaning activated but wrong lexical item retrieved.	Clarify without humiliation; model the precise word.
Gives up or jokes	Avoids exposing retrieval difficulty.	Reduce audience pressure and return to the idea.
Knows it in recognition but not recall	Recognition provides more external support than free retrieval.	Use options initially, then build independent retrieval.

iFollowing instructions: the classic behaviour trap

Why an instruction can fail	Example	Adjustment
Too many units	"Get your book, turn to 42, read the first section and answer 1–4."	Give one or two steps; visually list the sequence.
Unfamiliar vocabulary	"Annotate the persuasive devices."	Pre-teach "annotate" and "persuasive device" with a model.
Pronoun/reference ambiguity	"Put it over there after he is done with it."	Name the object, person and location.
Temporal/conditional language	"Do X before Y unless Z."	Make sequence/condition visible.
Fast delivery	Instruction disappears before processing is complete.	Pause after key information and allow response time.
Checking with yes/no	"Do you understand?" invites agreement.	Ask "What are you doing first?" or "Show me where you start."

iQuestions are language tasks, not neutral probes

Question type	Hidden demand	Why it matters
Who/what/where	Retrieve a specific person/object/place.	Usually more concrete, but vocabulary still matters.
When	Understand time and sequence.	Can be difficult when temporal concepts are weak.
Why	Infer cause/motive and construct an explanation.	A poor answer can be mistaken for lack of remorse or insight.
How	Organise sequence/process or explain mechanism.	Requires connected language, not just factual recall.
What would happen if...?	Conditional language plus prediction.	Heavy demand on language and abstract reasoning.
Tell me everything that happened	Open narrative organisation with no scaffolding.	Often one of the hardest ways to obtain a clear account.

iAbstract, temporal, conditional and figurative language

Language	Example	Risk if misunderstood
Temporal	before, after, until, while, earlier, later	Wrong sequence; appears not to follow routine or instruction.
Conditional	if, unless, except, provided that	Student takes one clause as absolute and misses the condition.
Comparative	more than, less likely, similar, opposite	Difficulty with maths, science and evaluation tasks.
Mental-state	assume, intend, regret, suspect, realise	Weak discussion of motives, emotions and social conflict.
Figurative	"pull your socks up", "read the room"	Literal or confused response.
Institutional	appropriate, responsibility, consequence, expectation	Discipline conversations can sound clear to adults but remain semantically vague to the student.

Reading the behaviour: "can't vs won't" & translation

Practical lens

Reference tool — informs practice, does not diagnose or label.

iEmotion language, insight and self-advocacy

Adult judgement	Alternative language hypothesis
"He cannot identify feelings."	He may experience emotion clearly but have weak emotion vocabulary or difficulty mapping internal states to words.
"She will not tell us what is wrong."	The language needed to describe internal state, sequence and cause may exceed available expressive language.
"He has no insight."	Insight may be partly present but difficult to organise into an explanation under questioning.
"She never asks for help."	Help-seeking requires recognising the problem, selecting language and tolerating social exposure.
"He just says I don't know."	This can be genuine lack of language access, overload, avoidance, uncertainty or all of these.

Do not overcorrect: language difficulty can explain why a student cannot express insight. It does not prove that insight is present. Observe behaviour and function as well as spoken explanation.

iWhy older students can look far more capable than they are

What fools adults	What may sit underneath
Fluent casual conversation	Familiar topics and scripts place much less demand on vocabulary depth and syntax.
Humour and banter	Strong social routines can conceal difficulty with academic/institutional language.
Swearing/slang used accurately	High-frequency, emotionally salient language can be learned well.
Arguing at length	Quantity of speech does not equal comprehension, precision or narrative organisation.
Good decoding	Reading words aloud can be much stronger than understanding the text.
Good knowledge in favourite topic	Deep familiar knowledge can support language in that domain while novel language remains difficult.
"Normal" one-to-one chat	Supportive adults naturally slow down, rephrase and supply context without realising it.

i"Can't" versus "won't" in language-heavy behaviour

Observation	Do not jump straight to	Check first
Does not start after instruction	Defiance/laziness	What exactly did the student understand? Can they state/show the first step?
Answers "whatever" during correction	Disrespect	Is the conversation too abstract, fast or emotionally loaded?
Gives inconsistent account	Lying	Can they sequence the event and understand the questions? What external evidence exists?
Copies another student	Cheating/dependence	Are they using peers to decode instructions or task expectations?
Avoids reading/writing	Motivation	Is oral-language or literacy demand exposing a skill gap?
Repeats the same social mistake	Does not care	Did the previous verbal feedback become an understandable, usable rule?

Still do functional assessment: DLD is not a universal answer for refusal. A student can understand perfectly and still choose not to comply. The point is to test comprehension before assigning motive.

iBehaviour translation table

What staff may write	Possible language contribution	Better question
"Doesn't listen"	Instruction comprehension, vocabulary, sentence length, processing time.	What part of the instruction can they demonstrate?
"Attention seeking"	Needs repeated clarification or adult scaffolding but cannot request it efficiently.	What information/support is the adult supplying each time?
"Argumentative"	Misunderstanding plus shame, rigid interpretation or poor repair language.	What meaning did the student assign to the adult's words?
"Lies"	Narrative/sequencing/word-retrieval difficulty may affect accuracy.	Is the error stable? What happens with neutral scaffolding and external evidence?
"No remorse"	Cannot explain internal state, cause/effect or perspective in expected language.	What does behaviour show after the event, not just verbal reflection?
"Lazy"	Task is language-dense or student cannot independently decode the next step.	Does performance change when language is simplified/modelled?
"Immature"	Language level may constrain social problem-solving and negotiation.	Which specific communication skill is below expectation?

Is it something else? Part 1

ADHD, autism, FASD, trauma/PTSD/dissociation, ODD/conduct problems.

Reference tool — informs practice, does not diagnose or label.

iDLD versus ADHD — and the very common overlap

Feature	DLD hypothesis	ADHD hypothesis
Misses instruction	Language not fully understood.	Attention shifted before/during instruction or working memory lost it.
Off-topic answer	Question/language interpretation or expressive organisation problem.	Impulsive response, attention shift, weak self-monitoring.
Sentence/grammar weakness	More characteristic of DLD when persistent across contexts.	Can be affected by attention, but structural language weakness requires assessment.
Word finding/vocabulary depth	Can be core DLD difficulty.	May occur, but not a defining ADHD symptom.
Inconsistent performance	Language familiarity/context can change performance.	State, interest, stimulation and attention often strongly alter performance.
Co-occurrence	DLD can coexist with ADHD.	ADHD does not explain away a separate language disorder.

A 2024 systematic review found meaningful overlap in language and executive-function presentations across ADHD and DLD and emphasised the need to assess both rather than assuming one explains the other.

iDLD versus autism

Question	DLD	Autism
Core diagnostic focus	Persistent language acquisition/use difficulty with functional impact.	Social-communication differences plus restricted/repetitive behaviours or interests.
Structural language	Often affected: vocabulary, grammar, comprehension, narrative.	Can range from strong to severely impaired.
Pragmatic language	Can be affected.	Often affected as part of the social-communication profile.
Restricted/repetitive behaviours	Not a DLD criterion.	Required within the broader autism diagnostic pattern.
Terminology when both present	CATALISE would describe clinically significant language impairment as language disorder associated with autism rather than DLD. Autism diagnosis does not mean language assessment/support is unnecessary.

iDLD versus FASD

Feature	DLD	FASD
Aetiology	No known differentiating biomedical cause; multifactorial neurodevelopmental condition.	Prenatal alcohol exposure is central to diagnosis.
Breadth	Primary impairment is language, though other neurodevelopmental difficulties may co-occur.	Current Australian diagnosis requires pervasive impairment across at least 3 neurodevelopmental domains plus functional impact.
Memory/executive function	Can be weaker in some individuals but not the defining diagnostic core.	Memory and executive function are explicit neurodevelopmental domains.
Language	Core difficulty.	Communication can be one impaired domain among a broader profile.
Label if FASD is diagnosed	Language difficulty is better described as language disorder associated with FASD. DLD should not be used to imply the known biomedical condition is absent.

iDLD versus trauma, PTSD and dissociation

Pattern	Language disorder possibility	Trauma-related possibility
Poor response to questions	Language comprehension/organisation difficulty across contexts.	Access drops particularly with threat, reminders, shame or dissociation.
Inconsistent account	Narrative language weakness, question comprehension, word finding.	Trauma memory, avoidance, arousal or dissociation may affect recall/communication.
Shutdown	Language demand exceeds capacity.	Threat response or dissociation.
Social misunderstanding	Pragmatic/inference language difficulty.	Hypervigilance or threat-biased interpretation.
Developmental course	Language difficulties emerge during development and persist.	Symptoms relate to exposure and trauma pattern; can coexist with DLD.

Important: trauma does not cause DLD, but trauma-exposed children have elevated rates of speech, language and communication needs. Assessment should avoid forcing one explanation when both may be relevant.

iDLD versus ODD / conduct problems

Behaviour	Language-based hypothesis	ODD/conduct hypothesis
Refuses instruction	Did not fully understand, cannot formulate clarification, task language too difficult.	Understands the demand but persistent oppositional pattern may be present.
Argues over wording	Literal/rigid interpretation or weak repair language.	Argument may be part of angry/irritable or defiant interaction pattern.
Breaks rules	Rule wording/conditions not understood or generalised.	Rule understood; violation occurs within broader pattern of defiance or rights violations.
Poor incident explanation	Narrative and expressive language difficulty.	May involve minimisation/deception; language still needs to be assessed.
Externalising behaviour	DLD is associated with higher behavioural risk at group level.	Externalising symptoms are not diagnostic evidence of DLD.

Is it something else? Part 2

Intellectual disability, dyslexia/SLD, Social (Pragmatic) Communication Disorder, hearing loss/APD, multilingual students.

Reference tool — informs practice, does not diagnose or label.

iDLD versus intellectual disability / borderline intellectual functioning

Issue	Current language-disorder reasoning
Normal IQ requirement	Rejected. DLD does not require a large gap between verbal and non-verbal abilities.
Low non-verbal ability	A child can have DLD with low non-verbal ability if criteria for intellectual disability are not met.
Intellectual disability present	Use language disorder associated with intellectual disability rather than DLD.
Adaptive functioning	Important to assess separately. Language can make adaptive ability look better or worse depending on task demands.
Why this matters at school	A verbally fluent student with borderline reasoning plus language disorder may be significantly overestimated because conversation masks both.

iDLD versus dyslexia and specific learning disorders

Domain	DLD	Dyslexia / reading disorder
Primary difficulty	Broad spoken-language learning/use.	Word reading, decoding, spelling and phonological aspects of literacy.
Reading aloud	May be affected or may look adequate.	Often a major area of difficulty.
Reading comprehension	High risk because oral language underpins comprehension.	Can also be weak, especially if DLD co-occurs.
Vocabulary/grammar/narrative	Often impaired.	May be relatively stronger in dyslexia without DLD.
Co-occurrence	Common enough that both should be considered. One label does not replace assessment of the other.

A systematic review of school achievement found students with DLD had difficulties across measured curriculum areas, with literacy the most studied domain.

iDLD versus Social (Pragmatic) Communication Disorder

Question	DLD	Social (Pragmatic) Communication Disorder
Main issue	Language learning/use can affect vocabulary, grammar, comprehension, narrative and pragmatics.	Persistent difficulty with the social use of verbal/non-verbal communication.
Structural language	Often a central part of the profile.	May be relatively intact compared with pragmatic use.
Inference/context	Can be difficult.	Often central.
Autism features	Not part of DLD.	SPCD requires that autism criteria are not met; restricted/repetitive behaviour would shift the differential toward autism.
Assessment	Speech pathology assessment of the whole language profile is essential.	Pragmatic complaints alone do not tell you which condition is present.

iDLD versus hearing loss / auditory processing complaints

Issue	What to remember
Hearing loss	Can produce language disorder associated with hearing loss and must be considered when language development is atypical.
"He hears me but does not process it"	That phrase can reflect language comprehension, attention, working memory, hearing, auditory-processing complaints or combinations. It is not a diagnosis.
Auditory Processing Disorder	Reported symptoms overlap substantially with ADHD, DLD, dyslexia and learning difficulties; differential assessment is important.
School action	Check hearing status when appropriate, reduce noise/load, and seek speech pathology/audiology input rather than assuming wilful ignoring.

iMultilingual students: language difference is not DLD

Principle	Practical meaning
Multilingualism does not cause DLD	Learning more than one language is not a communication disorder and should not be "treated" by dropping the home language.
DLD affects the language-learning system	A genuine disorder should be evident across the child's languages, interpreted relative to exposure and opportunity.
English-only low scores can mislead	Limited exposure to English can produce low English performance without a disorder.
Assessment must use the language history	Consider amount, age, context and quality of exposure in each language; use interpreters/dynamic assessment and multilingual data where possible.
Home language is an asset	Maintaining it supports identity, family communication and access to skills already developed in that language.

Speech Pathology Australia explicitly states that multilingualism does not cause communication disorders and that a true disorder affects all of the child's languages.

Assessment & what educators can document

Assessment

Reference tool — informs practice, does not diagnose or label.

iWhat a proper DLD assessment looks like

Component	Why it matters
Developmental and family history	Language trajectory, risk factors, previous services and functional concerns.
Hearing status	Rules out or identifies hearing-related contribution.
Standardised language assessment	Samples vocabulary, grammar, comprehension and other language domains using age-referenced measures.
Language sample / narrative	Shows connected language that formal subtests can miss.
Functional reports	Parents, teachers and the young person show real-world impact across settings.
Classroom observation	Shows how language demands interact with attention, behaviour and teaching.
Dynamic assessment / response to support	Can clarify learning potential and is especially useful when standard norms are a poor fit.
Differential assessment	Considers ADHD, autism, intellectual disability, hearing, learning disorder, neurological conditions, multilingual exposure and other explanations.

No magic test score: CATALISE and RCSLT caution against diagnosing language disorder from one universal cut-off. Test scores matter, but prognosis, functional impact, context and converging evidence matter too.

iWhat educators can observe and document

Observe	Useful example
Instruction comprehension	Which sentence length, vocabulary or number of steps reliably causes errors?
Question comprehension	Does performance change between who/what questions and why/how/conditional questions?
Narrative ability	Can the student explain an event in sequence without heavy adult scaffolding?
Vocabulary	Which curriculum words are used vaguely, confused or forgotten?
Repair behaviour	What happens when the student does not understand: asks, copies, jokes, argues, freezes, leaves?
Modality difference	Does a model, visual or written example produce a large improvement over oral explanation alone?
Context	Do familiar topics/routines mask the problem while novel tasks expose it?
Functional impact	How does language affect independence, peer conflict, assessment, behaviour and access to curriculum?

Academic, literacy & social impact

Impact

Reference tool — informs practice, does not diagnose or label.

iAcademic impact across the curriculum

Area	Language demands that can create difficulty
English	Vocabulary, syntax, inference, narrative, figurative language, written organisation.
Maths	Word problems, comparative/relational terms, explanation of reasoning, sequence language.
Science	Technical vocabulary, passive constructions, causal language, multi-step procedures.
HASS	Dense text, chronology, abstract concepts, cause/effect, perspective and evidence.
Health/PE	Rapid verbal instructions, rules, team negotiation, body/emotion vocabulary.
VET/practical	Safety language, procedural sequencing, conditional instructions and workplace communication.
Assessment	Questions can test language comprehension as much as subject knowledge.

Across 44 studies in a systematic review, students with DLD showed lower group-level achievement across all measured curriculum areas, although individual profiles were highly variable.

iLiteracy: why oral language keeps mattering after decoding

Literacy task	DLD-related risk
Reading comprehension	Weak vocabulary, grammar, inference and discourse comprehension can limit meaning even when words are decoded accurately.
Written expression	Generating, organising and grammatically encoding ideas places heavy expressive-language demands.
Spelling/word learning	Phonological and lexical weaknesses can interact with literacy development.
Exam questions	Complex syntax and command verbs can obscure what the question is asking.
Summarising	Requires identifying main ideas, suppressing detail and expressing relationships concisely.
Research tasks	Multiple texts, abstract vocabulary and written synthesis greatly increase language load.

Do not stop at reading accuracy: a student who reads a paragraph aloud fluently may still have understood very little of it.

iMaths can be a language subject too

Language demand	Examples	Possible support
Relational terms	more than, fewer, difference, equivalent, between	Teach and display the exact relational vocabulary.
Sequence	first, next, then, before, after	Use visual step sequences and worked examples.
Word problems	irrelevant detail, pronouns, embedded clauses	Separate the mathematical information from the story wording.
Justification	explain, prove, compare, describe	Provide sentence frames and model what a sufficient explanation sounds like.
Generalisation	same operation described with different words	Explicitly map multiple phrases to the same mathematical relationship.

iSocial, emotional and peer impact

Risk area	How language can contribute
Peer conflict	Misread intent, weak repair, difficulty explaining own perspective and negotiating.
Victimisation/exclusion	Communication differences can make social entry and conflict repair harder.
Anxiety	Repeated misunderstanding, public failure and unpredictable language demands can increase social/academic anxiety.
Low self-esteem	The student may know they keep getting things wrong without understanding why.
Externalising behaviour	Frustration, misunderstanding and repeated correction can contribute to behavioural difficulties.
Isolation	Conversation becomes more demanding as peers rely on inference, humour and shared narratives.

A 2025 systematic review confirmed higher social-emotional difficulties and poorer quality-of-life outcomes at group level, while also showing substantial variation between individuals.

Adolescence & justice-system risk

Trajectory

Reference tool — informs practice, does not diagnose or label.

iAdolescence: when language becomes more invisible and more important

Rising demand	Why DLD may become more visible
Abstract curriculum	Vocabulary, syntax and inference grow more complex while explicit language teaching often decreases.
Multiple teachers	Every adult uses different wording, routines and implied expectations.
Peer nuance	Sarcasm, flirting, status, indirect conflict and group subtext depend heavily on pragmatic inference.
Independence	Young person must clarify misunderstandings and advocate for support without an adult doing it for them.
Disciplinary language	Expectations, consequences, reflection and restorative conversations become more abstract.
Future pathways	Applications, interviews, workplace instructions and training rely heavily on oral and written language.

!DLD and justice-system / high-risk contexts

Language disorder is reported at substantially higher rates in youth-offending populations than in general community samples. This does not mean DLD causes offending. It means language vulnerability is important when young people are being questioned, sanctioned, counselled or expected to understand complex rules.

Communication demand	Potential vulnerability
Rapid questioning	Insufficient time to process question syntax and retrieve an answer.
Why/how questions	High demand on causal, inferential and narrative language.
Long cautions/rules	May sound understood without the young person retaining the exact meaning.
Retelling incidents	Sequence, context and precise vocabulary may be weak.
Changing question wording	The young person may treat semantically similar questions as different demands.
Written conditions	Complex institutional vocabulary can exceed functional comprehension.

Practice implication: use plain language, one question at a time, allow processing time, check meaning through open recall, and do not treat "yes" as proof of comprehension.

Strategy toolkit

Strategy

Reference tool — informs practice, does not diagnose or label.

✓Adult language adjustments that reduce unnecessary failure

Instead of	Try
Long explanation before the action	Give the action first, then the minimum explanation needed.
"You need to show more responsibility."	Name the observable action: "Put the Chromebook in the tray before you leave."
Three instructions in one sentence	One or two steps plus a visual sequence.
Repeating the same sentence louder	Rephrase with simpler syntax or show/model the meaning.
Rapid-fire questioning	Ask one question, wait, then follow up.
Indirect hints	Use direct, respectful language when the action is important.
Novel wording every time	Use consistent phrases for recurring routines and expectations.
Talking while the student is doing a difficult task	Reduce competing verbal input when the task already carries high language/cognitive load.

✓How to check understanding without making the student say "yes"

Weak check	Better check	Why
"Do you understand?"	"What are you doing first?"	Requires retrieval of the actual instruction.
"Got it?"	"Show me where you start."	Demonstration reduces expressive-language demand.
"What did I just say?"	"Tell me the two jobs in your own words."	Checks meaning rather than verbatim repetition.
"Why aren't you doing it?"	"What part is unclear — the word, the steps or where to start?"	Provides a structured route to clarification.
"You know the rule."	"What is the rule here? What does it look like right now?"	Checks whether the rule is accessible in this context.

Intervention evidence & working guide

Evidence & practice

Reference tool — informs practice, does not diagnose or label.

iIntervention and teaching: what the evidence supports

Target	Evidence-informed approach	Caution
Vocabulary	Explicitly teach meaning and word form; multiple examples; retrieval practice; revisit in relevant contexts.	Exposure alone may not be enough; gains may stay specific to taught words.
Grammar/syntax	Explicit teaching of sentence structures, often with visual/metalinguistic supports, has evidence for some school-age groups.	No single programme fits every profile.
Narrative	Teach story/event structure, causal links and how much context a listener needs.	Improvement in trained structures does not guarantee spontaneous generalisation.
Comprehension	Teach vocabulary, grammar and narrative comprehension directly; scaffold processing.	Evidence is heterogeneous and intervention should be individualised.
Classroom support	Teacher-SLP collaboration and whole-class oral-language strategies can help access and may improve outcomes.	The 2026 whole-class evidence base remains relatively small and varied.
Functional communication	Teach clarification, repair, self-advocacy and scripts for high-demand situations.	Do not replace language teaching with permanent adult rescue.

Systematic reviews support targeted oral-language intervention, particularly explicit vocabulary and grammatical approaches, while also noting heterogeneity, limited generalisation and the need to match treatment to the individual language profile.

✓One-page working guide for school behaviour

What you see	Language question to ask	Immediate adjustment
Student does nothing after instruction	Did they understand the words, sentence and sequence?	One step; model; visual cue; ask for first action.
"I don't know" to every incident question	Is question type/narrative demand too high?	Regulate first; ask concrete who/what/where; build sequence.
Argues about exact wording	Is meaning genuinely unclear or interpreted literally?	State the concrete expectation; avoid abstract moral language.
Copies peers	Are peers functioning as an instruction decoder?	Give a visible model/sequence rather than removing the scaffold blindly.
Gives a fluent but muddled account	Does speech quantity exceed narrative precision?	Clarify one event at a time; use timeline/visual supports.
Reads well but cannot answer questions	Is comprehension weaker than decoding?	Pre-teach vocabulary; chunk text; teach inference explicitly.
Looks inattentive in language-heavy lessons	Is language load driving disengagement?	Reduce sentence length, define vocabulary, add visual information.
Says "yes" then does the wrong thing	Was agreement mistaken for comprehension?	Use open recall or demonstration to check meaning.

Bottom line: if a student repeatedly fails after spoken explanation, stop assuming that more spoken explanation is the solution.

Evidence base & resources

This handbook prioritises Australian professional information and international consensus/review evidence. DLD terminology continues to evolve across diagnostic systems, so older reports may use SLI, receptive/expressive language disorder or language impairment for overlapping populations.

Reference tool — informs practice, does not diagnose or label.

Speech Pathology Australia — Developmental language disorder (DLD) fact sheet speechpathologyaustralia.org.au
Bishop DVM et al. (2017) — Phase 2 of CATALISE: terminology for problems with language development pmc.ncbi.nlm.nih.gov/articles/PMC5638113
RCSLT — Clinical information on developmental language disorder rcslt.org — DLD Clinical Information
Calder SD et al. (2022) — Prevalence of and potential risk factors for DLD at 10 years in the Australian Raine Study pmc.ncbi.nlm.nih.gov/articles/PMC9804624
Ziegenfusz S et al. (2022) — Academic achievement of primary/secondary students with DLD: systematic review pmc.ncbi.nlm.nih.gov/articles/PMC9620692
Mendez-Freije I et al. (2024) — Language skills in children with ADHD and DLD: systematic review pmc.ncbi.nlm.nih.gov/articles/PMC10814652
van Barreveld M et al. (2025) — Social-emotional functioning and quality of life in language disorders: systematic review pmc.ncbi.nlm.nih.gov/articles/PMC12012875
Zupan B et al. (2022) — Language disorder and internalizing mental-health problems in youth offenders: systematic review pmc.ncbi.nlm.nih.gov/articles/PMC9796836
Ansari R et al. (2025) — Vocabulary interventions for children with DLD: systematic review pmc.ncbi.nlm.nih.gov/articles/PMC11962024
Tarvainen S et al. (2021) — Oral language comprehension interventions in school-age DLD: scoping review pmc.ncbi.nlm.nih.gov/articles/PMC9620681
Armstrong R et al. (2026) — Effective whole-class oral language interventions for students with DLD: systematic review pmc.ncbi.nlm.nih.gov/articles/PMC13247385
Speech Pathology Australia — Supporting multilingual children's communication development speechpathologyaustralia.org.au
RCSLT — DLD: questions on diagnosis and support rcslt.org — Diagnosis and Support
Adlof SM, Hogan TP (2018) — Understanding dyslexia in the context of developmental language disorders pmc.ncbi.nlm.nih.gov/articles/PMC6430503