Definition
Developmental Language Disorder is a lifelong condition affecting the ability to understand and use spoken language, with no obvious cause and no associated condition (such as autism or a hearing impairment) accounting for it. It affects around 7% of UK children (roughly two in every classroom) and is set out in the CATALISE consortium 2017 criteria, which most UK SLT teams use.
In context for parents
Key checkpoints
- DLD is a lifelong condition affecting understanding and use of spoken language, with no obvious cause.
- Affects roughly 7% of UK children (about two in every classroom).
- CATALISE 2017 international consensus replaced older terms (Specific Language Impairment, language delay) with DLD.
- Best evidence supports little-and-often SLT intervention (RCSLT) over weekly blocks.
- A DLD diagnosis often crosses the EHC needs assessment threshold, particularly with CELF-5 UK standard scores at or below the 2nd centile.
DLD is the diagnosis the CATALISE 2017 international consensus put in place to replace older terms (Specific Language Impairment, language delay, language disorder) that did not travel well between clinicians. A child meets DLD criteria when their language difficulties are persistent (not catching up), functionally significant (affecting school, friendships, or family life), and not explained by another condition.
In a Year 1 classroom, DLD looks like the child who has missed the joke when everyone else has laughed, who hears "first put your coat on, then come to the carpet" and arrives at the carpet without their coat, and whose written work in Year 4 reads like the work of a six-year-old not because of dyslexia but because the underlying spoken language is below age expectation. The intelligence is intact; the language system is not pulling its weight.
What works: regular, distributed SLT intervention (the Royal College of Speech and Language Therapists evidence base supports little-and-often over once-weekly blocks), with the school's TA delivering the targeted programme under SLT supervision. Pre-teaching of vocabulary before each new topic, visual supports for narrative structure (Colourful Semantics, Shape Coding), and adapted comprehension materials make the rest of the curriculum accessible.
A DLD diagnosis often crosses the EHC needs assessment threshold, particularly where standard scores on the CELF-5 UK or similar place the child at or below the 2nd centile and where a 1:1 or small-group SLT-supervised programme is needed regularly. Section F should quantify the SLT hours, not just say "access to SLT".
Related terms
The terms parents most often see alongside Developmental Language Disorder.
Speech, Language and Communication Needs(SLCN)
An umbrella term for difficulties with understanding language, using language, speaking clearly, or interacting socially. SLCN is one of the four broad SEND areas in the Code of Practice.
Speech and Language Therapist(SLT)
An HCPC-registered specialist who assesses and treats children with speech, language, communication, and swallowing needs. SLTs contribute to EHCPs and deliver targeted therapy.
Auditory Processing Disorder(APD)
Difficulty making sense of sounds despite normal hearing. Children may mishear instructions, struggle in noisy classrooms, or need extra time to process spoken language.
Where parents ask about this
Parents usually find this page after years of "he's just a late talker", after CELF-5 scores have come back at the 2nd or 5th centile, or before a tribunal where the LA has stripped quantified SLT out of Section F. Searches include "DLD diagnosis UK", "DLD EHCP Section F wording", and "is DLD the same as SLCN". A Beaakon SaLT can carry out a full CATALISE-compliant assessment, identify whether DLD is the right formulation or whether the picture is autism with language difficulty, and write Section F provision that is specific, quantified, and survives LA amendment.
References
The primary legislation, statutory guidance, research, and clinical tools this page draws on.
- Bishop, Snowling, Thompson, Greenhalgh and the CATALISE consortium (2017): Phase 2 criteria for identifying language disorders
- Royal College of Speech and Language Therapists (RCSLT): DLD evidence base
- Clinical Evaluation of Language Fundamentals, 5th edition UK (CELF-5 UK): Pearson
- Children and Families Act 2014, section 36
- SEND Code of Practice 6.28–6.30