Developmental language disorders: A teacher's guide

What is Developmental Language Disorder (DLD) in children?

Developmental Language Disorder (DLD) is a neurodevelopmental condition that affects 1 in 14 children's ability to understand and use language throughout their lives. It impacts more pupils than autism and dyslexia combined, yet remains significantly under-identified in UK classrooms. DLD was previously known as specific language impairment (SLI) or expressive-receptive language disorder.

Development language disorder (DLD), considered a neurodevelopmental disorder, that falls under special educational needs. It is a long-life condition that affects the child in using and understanding language. It is also known as specific language impairment (SLI), speech disorder, speech-language impairment, or expressive-receptive language disorder. All these names come under the umbrella term of a developmental speech disorder.

Children with developmental language difficulties may be at risk of working below their age range level. Children with developmental language difficulties may be struggling with social skills and low educational attainment. The child at the age of 4 has a more stable language ability, therefore the developmental language disorder can be measured accurately at the age of 4. That does not mean that there are no signs of developmental language disorder appearing on the child before age 4 but it is more accurately diagnosed at the age of 4. 

Language skills are a vital tool for everyday life speech, language and communication needs, school-age children need verbal capabilities to be able to communicate with others and express themselves. It is estimated that 1 out of 14 children may have difficulty in using phrasing skills or have a developmental language disorder.

A useful exercise for understanding oral skills is to place yourself in the child's situation, imagine yourself not being able to express that you are angry. Another example is that you are not able to understand what task you should do while your boss is giving you a deadline to finish it. Imagine how stressful these feelings are? This guide will go in-depth on developmental language disorder and look at what positive steps teachers can take in identifying speech issues.

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The CATALISE Consensus: Why DLD Replaced Specific Language Impairment

For decades, children with persistent language difficulties not explained by hearing loss or intellectual disability were labelled with 'Specific Language Impairment', or SLI. The term seemed precise, but its definition rested on exclusionary criteria: a child qualified only if their language scores were disproportionately low relative to their non-verbal IQ. In practice, that requirement locked many children out of diagnosis and, therefore, out of support. A child with broadly low cognitive ability whose language was nonetheless disproportionately poor might be told that the language difficulty was simply 'part of' a more general profile, even though the functional impact on communication was identical.

The CATALISE project, a two-round Delphi consensus study led by Dorothy Bishop and an international panel of researchers and clinicians, replaced SLI with a cleaner, more inclusive framework (Bishop et al., 2016, 2017). 'Developmental Language Disorder', or DLD, is now the agreed term for a language disorder that causes functional difficulties in everyday life and is not associated with a known biomedical condition such as a brain injury, autism spectrum condition, or sensorineural hearing loss. Crucially, DLD is not diagnosed by exclusion of low IQ. A child can have DLD alongside a broader learning difficulty if their language needs are sufficiently severe and require targeted intervention. The non-verbal discrepancy criterion, which had no reliable predictive value for treatment response, was abandoned.

The functional impact criterion is the part of the CATALISE definition that matters most to teachers. Language difficulties qualify as DLD when they affect participation: following multi-step instructions in class, understanding the language of a text, formulating answers in discussion, or accessing a curriculum delivered predominantly through talk. A child who sounds fluent in playground conversation but cannot process teacher explanations at pace, or who struggles to retell a story in sequence, may well have DLD even though a superficial assessment might suggest otherwise. Bishop et al. (2017) estimated that DLD affects approximately two children in every classroom of thirty, making it one of the most common neurodevelopmental conditions teachers encounter, yet consistently one of the least recognised.

For schools, the shift from SLI to DLD carries two practical implications. First, referral to a speech and language therapist no longer requires a child to have 'normal' non-verbal ability. If functional language difficulties are present and persistent, that is sufficient grounds for a specialist assessment. Second, 'language disorder' is now distinguishable from 'language delay', a distinction the CATALISE panel was explicit about. Language delay implies a slower trajectory that eventually converges on age-expected levels; DLD implies a persistent profile that requires long-term support rather than watchful waiting. Knowing which pattern you are looking at shapes both your expectations and your provision.

When can teachers identify signs of DLD in pupils?

Teachers can observe early warning signs of DLD before age 4, though formal diagnosis typically occurs at age 4 when language abilities become more stable. Key indicators include difficulty following instructions, limited vocabulary teaching compared to peers, and struggles with storytelling or explaining ideas. Early identification allows teachers to advocate for intervention before formal assessment.

Obverse the skills of childrens development milestones, to ensure that the developmental skills are at the proper age range. As with any impairment, children with language disorders will have early signs that careers and parents need to take into consideration. Here are some signs of developmental language disorder:

• Difficulties in oral phrasing competence:  they may have difficulties in translating their ideas into words and sentences. That is leading to obstacles with social situations and communication difficulties.
• Difficulty with expressive wording: Children with DLD may struggle to express their feeling and thoughts. Also, difficulties with finding the right words to describe their feelings. As a result, they may be less talkative than others
• Speech sound disorder: which means skipping sounds out, for example; saying nan instead of banana. Moreover, children with DLD may use wrong sounds, wed instead of red. 
• Weak language skills:
1. Children with DLD may struggle with listening, reading, writing, and speaking skills.
2. Children with DLD may have difficulty remembering what they heard, struggle to pay attention to the given instructions
3. Having difficulty remembering and learning new words and their vocabulary as result they struggle in reading and writing.
4. Also, they may not be secured to use correct grammar during writing and speaking.
5. Difficulty in forming up a sentence 
6. Difficulty in speaking skills as they may not be able to re-tell a story.  
• Difficulty with receptive language: difficulty with following verbal instructions, answering questions, misunderstanding what has been said to them. 

All these conditions may result in misbehaving or anxiety for the child, as the child with DLD has obstacles with communication skills. 

All of the above are common signs with DLD but it does not mean that all of these signs will appear on the child. Participators should deal according to each individual child's needs.  



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What causes Developmental Language Disorder in children?

DLD is a neurodevelopmental condition with no single identified cause, though it often runs in families suggesting a genetic component. Risk factors include family history of language difficulties, premature birth, and low birth weight. Unlike other language delays, DLD is not caused by hearing problems, low intelligence, or lack of language exposure.

Language development requires a multitude of interconnected skills including hearing, seeing and comprehending information. There are many studies about DLD, but there is no current study that was able to answer why some children have DLD and some do not. Some studies were able to highlight a common condition that may be resulting in having DLD.

• Biomedical Condition: such as having autism spectrum disorders, genetic conditions such as down syndrome, where the child has obstacles t o communication and learning in everyday life. Different ways of the child's brain and howthey respond to communication and language development. 
• Genetic Condition: There is increasing confirmation that DLD may be inherited in families. However, there is no confirmation that genetic causes DLD, further studies are in progress.
• Environmental Factors: Premature birth and low birth weight have been associated with language development. However, these factors are not directly linked to DLD. 

Although these conditions may cause DLD, consider that DLD can also occur with no known cause.

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DLD and Literacy: Why Reading Difficulties Often Begin in Language

Reading is not a single skill. Gough and Tunmer (1986) proposed the Simple View of Reading as a multiplication of two components: decoding and language comprehension. Decoding is the ability to convert print into spoken words through phonics knowledge; language comprehension is the ability to understand the meaning of those words once decoded. Both components are necessary, and a weakness in either produces reading difficulties. Children with DLD typically have adequate or even strong decoding skills once they have received systematic phonics instruction. Their reading failures emerge at the comprehension stage, where weak vocabulary, poor inference-making, and limited sentence-level processing converge to undermine meaning-making from text.

Catts et al. (2002) followed a large cohort of children from kindergarten to fourth grade and identified four reader profiles. Poor decoders with adequate comprehension ('dyslexic' readers), poor comprehenders with adequate decoding ('language learning disabled' readers), children poor on both dimensions, and typically developing readers. The group with poor comprehension and adequate decoding was disproportionately made up of children who had been identified with language difficulties in preschool. Their word-reading accuracy was often grade-appropriate, which meant their reading problems were invisible until comprehension demands increased. By the time these children were expected to read to learn rather than learn to read, the gap between their print access and their text understanding had become educationally significant.

This profile has direct consequences for how you interpret assessment data. A child with DLD who scores at age level on a standardised phonics screen but performs poorly on reading comprehension tasks is not 'doing well at reading'. She is decoding successfully but comprehending poorly, and the gap will widen as texts become more syntactically complex and vocabulary more specialised across the curriculum. Screening for reading difficulties in children known or suspected to have DLD should always include a measure of listening comprehension alongside decoding, because listening comprehension is a better proxy for language ability and a stronger predictor of reading comprehension outcomes in this population.

Vocabulary knowledge is the mechanism that links DLD to comprehension failure. Children with DLD typically have smaller vocabularies, slower lexical retrieval, and shallower word knowledge than their peers: they may recognise a word without knowing enough about it to use it in comprehension (Nation and Snowling, 1998). Classroom strategies that address this overlap include pre-teaching key vocabulary before a reading task, building semantic networks around topic words rather than presenting isolated definitions, and using structured discussion to deepen word knowledge through multiple exposures in varied contexts. Reading comprehension strategies that build background knowledge before a text are particularly valuable for pupils whose language profiles make inference-making slow and effortful.

How can teachers support pupils with DLD in the classroom?

Teachers play a crucial role in supporting pupils with DLD. Practical strategies include simplifying instructions, using graphic organisers aids, pre-teaching vocabulary, and providing extra time for processing information. Creating a language-rich classroom environment with opportunities for communication and collaboration is also essential.

As teachers, we need to remember that DLD can impact the children's learning abilities, therefore be patient with the students. Here are some steps that teachers can take in order to support DLD students:

• Communicate with simple and clear language to ensure the child's understanding of what is being said.
• Use visual aids such as flashcards, images, and diagrams to help the students understand and remember new information.
• Pre-teach key vocabulary before starting a new topic or lesson, to ensure that the students are familiar with the words before they encounter them in context.
• Provide extra time for the students to process information and complete tasks.
• Encourage the students to ask questions and clarify their understanding.
• Break down complex tasks into smaller, more manageable steps.
• Use assistive technology such as speech-to-text software, to help the students with writing and communication.
• Create a language-rich classroom environment with lots of opportunities for communication and collaboration.
• Work with parents and other professionals to develop an individualised education plan (IEP) that meets the specific needs of the students.
• Provide positive reinforcement and encouragement to help the students build confidence and motivation.

Teachers can play a key role in supporting pupils with DLD in the classroom, and should implement all the steps mentioned above to ensure the child can improve. Creating a classroom environment where pupils are supported to express themselves and feel secured will increase the child's skills.

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NELI: What the Evidence Says About Early Language Intervention at Scale

The Nuffield Early Language Intervention (NELI) is a structured oral language programme designed for reception-age children in the bottom 20 per cent for language ability. Developed at the University of Oxford and evaluated by the Education Endowment Foundation, NELI delivers ten weeks of daily language sessions: twenty minutes of small-group work with three to four children plus ten minutes of individual practice. Sessions are led by a trained teaching assistant using scripted lesson plans that cover vocabulary, listening skills, narrative, and phonological awareness. The EEF's randomised controlled trial found that children who received NELI made, on average, three additional months of progress in language ability compared with a control group, a finding that was consistent across school contexts and pupil demographics (EEF, 2018).

Fricke et al. (2017) conducted an earlier efficacy trial of NELI that informed the EEF evaluation. Their study found significant gains not only in oral language but in early literacy skills, supporting the view that oral language intervention in the reception year has downstream effects on reading. The gains were strongest for children whose language difficulties were most severe at entry, suggesting that early, targeted intervention is particularly effective when it reaches children with DLD profiles before formal literacy teaching begins. Fricke and colleagues also noted that the structured scripted format of NELI was important for implementation fidelity: programmes where teaching assistants were given flexible frameworks rather than detailed scripts showed more variable outcomes, because the precision of vocabulary modelling and question sequencing is what drives progress in children with language disorders.

Implementation quality is where NELI's promise and its challenges converge. The EEF scale-up evaluation found that effect sizes in real-world conditions were somewhat smaller than in the efficacy trial, a pattern common in educational interventions when they move from controlled research settings into routine school practice. The most common barriers were inconsistent session delivery, insufficient training follow-up, and timetable pressures that reduced the frequency of individual top-up sessions. Schools that maintained daily delivery and that had a named member of staff responsible for monitoring fidelity achieved results closer to the efficacy trial findings. The lesson for school leaders is that NELI is not a self-running programme: it requires protected timetable slots, a trained teaching assistant who receives ongoing coaching, and a system for checking whether children who are not progressing need a speech and language therapy referral alongside the programme.

NELI fills a specific gap in provision that many schools have struggled to address: whole-class language work does not meet the needs of children with DLD, and full speech and language therapy caseloads mean that most children with mild to moderate language difficulties receive no specialist intervention at all. A tiered model places NELI at Tier 2, sitting between quality-first classroom language teaching at Tier 1 and direct SLT work at Tier 3. Children who complete NELI without reaching age-expected language levels should be flagged for Tier 3 assessment rather than being cycled through the programme again. That escalation pathway matters: for children with DLD, a ten-week language boost is rarely sufficient, and the risk of over-relying on NELI as a substitute for specialist assessment is that it delays the more intensive support some children need.

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Narrative Assessment: Why Storytelling Reveals More Than Standardised Tests

Standardised language assessments measure discrete skills: sentence repetition, vocabulary breadth, grammatical accuracy. They are useful for identifying whether a child's language falls outside the expected range, but they do not tell you much about how a child uses language in real communicative contexts. Narrative assessment addresses this gap. Asking a child to retell a story or generate an original account from a picture sequence places simultaneous demands on vocabulary, sentence structure, event sequencing, causal reasoning, and the ability to take a listener's perspective. Liles (1993) argued that narrative competence is precisely the skill domain most predictive of academic language success because it requires a child to integrate all the components of language into a sustained, coherent discourse.

Standardised narrative measures provide a more ecologically valid picture of DLD than sentence-level tests alone. The Bus Story Test (Renfrew, 1969; revised by Cowling, 2014) asks a child to retell a short illustrated story about a bus that runs away from its driver. It yields scores for information content and mean sentence length, and its norms allow comparison with age-matched peers. Research consistently shows that children with DLD produce Bus Story retellings with fewer story elements, shorter sentences, and more ambiguous reference than typically developing children of the same age, even when their performance on discrete grammatical tasks is closer to the norm. Other measures, including the Edmonton Narrative Norms Instrument (Schneider et al., 2005) and the Test of Narrative Language (Gillam and Pearce, 2013), allow more detailed analysis of story grammar components: setting, initiating event, internal response, attempt, consequence, and resolution.

Narrative ability does not just reveal language difficulty; it predicts later outcomes. Petersen et al. (2010) developed the Supporting Knowledge in Language and Literacy (SKILL) intervention, a manualised narrative programme delivered in small groups. The programme teaches story grammar components explicitly, uses visual supports such as story grammar icons, and practises retelling through graduated steps from supported to independent production. In a randomised controlled trial, children who received SKILL showed significantly greater gains in narrative quality, language structure, and reading comprehension than children in a control condition. Petersen et al. found that narrative gains predicted literacy gains, confirming Liles's theoretical claim that narrative is an integrative language skill with cross-domain transfer.

For class teachers, narrative tasks offer an assessment method that requires no specialist training to administer and yields rich observational data. Asking a pupil to retell a short picture-book story and recording the retelling for later analysis takes ten minutes. You are listening for whether the child establishes who the characters are, whether events are sequenced causally rather than listed chronologically, whether the problem and resolution are included, and whether the child uses appropriate past tense and third-person pronouns consistently throughout. A child who produces a fragmented retelling with missing causal links and pronoun confusion is showing you a DLD profile. That observation is a legitimate trigger for structured scaffolding in class and for a referral conversation with your school's SENCO.

Conclusion

Developmental Language Disorder presents unique challenges for pupils, but with increased awareness and targeted support, teachers can significantly improve their learning outcomes and overall well-being. Early identification and intervention are paramount, allowing for tailored strategies that address individual needs and creates a more inclusive classroom environment.

By implementing the strategies outlined in this guide, such as simplifying instructions, utilising visual aids, and pre-teaching vocabulary, teachers can helps pupils with DLD to overcome communication barriers and access the curriculum effectively. Remember, patience, understanding, and collaboration with parents and specialists are key to creating a supportive and enriching learning experience for every child.

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Written by the Structural Learning Research Team

Reviewed by Paul Main, Founder & Educational Consultant at Structural Learning

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Frequently Asked Questions

What is Developmental Language Disorder and how does it affect pupils?

DLD is a neurodevelopmental condition that makes it difficult for children to understand and use spoken language. It is a lifelong condition that affects around one in fourteen children; it is often hidden and can impact social skills, literacy, and academic progress throughout a child's school career.

How do teachers support children with DLD in the classroom?

Teachers can support these learners by using visual aids, simplifying verbal instructions, and providing extra time for processing information. Strategies such as modelling correct language and pre-teaching vocabulary help pupils access the curriculum and participate in lessons more effectively.

What are the early warning signs of DLD in primary school children?

Common signs include difficulty following complex instructions, limited vocabulary compared to peers, and trouble organising thoughts into sentences. Some pupils may skip sounds in words or struggle to retell simple stories; these indicators often become more apparent as language demands increase in school.

What does the research say about the prevalence of DLD in UK schools?

Research indicates that DLD is significantly more common than autism or dyslexia, affecting approximately two children in every class of thirty. Despite its high prevalence, many children remain undiagnosed and may be mislabelled as having behavioural issues or general learning difficulties.

What are common mistakes when supporting pupils with speech and language needs?

A frequent error is assuming a child is being disobedient when they have simply failed to process a verbal instruction. Another mistake is relying solely on spoken communication without providing visual scaffolds, which can lead to increased anxiety and disengagement for the learner.

What are the benefits of early identification for children with language disorders?

Early identification allows teachers to put targeted support in place before a child falls significantly behind their peers. It helps reduce the risk of long term emotional difficulties, improves social interaction, and ensures that the child can develop the communication skills necessary for everyday life.

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structural-learning.com | © 2026 | Based on EEF research. For guidance only — adapt to your school context.

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Further Reading

DLD research

Language disorder interventions

Supporting language difficulties

• Bishop, D. V. M. (2017). Why is it so hard to reach agreement on terminology? The case of developmental language disorder (DLD). *International Journal of Language & Communication Disorders*, *52*(6), 671-680.
• Dockrell, J., & Lindsay, G. (2001). Children with specific speech and language difficulties: the teachers' perspective. *British Journal of Special Education*, *28*(3), 103-111.
• Law, J., Charlton, J., & Asmussen, K. (2017). Language as a child student wellbeing indicator. *What Works Wellbeing*.
• Norbury, C. F., Gooch, D., Baird, G., Charman, T., Simonoff, E., Vamvakas, G., & Pickles, A. (2016). The impact of nonverbal ability on prevalence and clinical presentation of language disorder: evidence from a population-based study. *Journal of Child Psychology and Psychiatry*, *57*(11), 1247-1257.