Understanding Developmental Language Disorder (DLD)

Last Updated: 16 January 2026

What is DLD?

Developmental Language Disorder (DLD) is a common, lifelong condition that interferes with how children learn, understand and use language, impacting communication, social interactions, and academic progress.These language difficulties are not explained by other conditions, such as hearing loss or autism, or by external circumstances, such as lack of exposure to language.

What causes DLD?

The exact causes of DLD are still not completely understood, but research suggests that it may be related to complex interactions between:

Genetics: Family history plays a role, with some children being more likely to experience DLD if their parents or siblings have a history of language difficulties.
Brain Development: Differences in brain structure and function may contribute to DLD.
Environmental Factors: Limited exposure to language, hearing difficulties, or other environmental factors may impact language development.
Developmental Delays: Other neurodevelopmental delays, such as cognitive or motor skills delays, Autism Spectrum Disorder, or dyslexia may co-occur with DLD.

Does learning another language cause DLD?

No. Learning more than one language at a time does not cause DLD. The disorder can, however, affect both multilingual children and children who speak only one language. For multilingual children, DLD will impact all languages spoken by a child and the disorder will became apparent in both languages.

How is DLD diagnosed?

A comprehensive assessment by a Speech Pathologist is the best way to diagnose DLD. The SP will use standardised assessments to evaluate your child's:

Understanding and use of language (receptive skills)
Vocabulary and grammar skills (expressive skills)
Ability to communicate effectively
Social skills
Hearing and cognitive abilities by referring to other professionals

What are early signs my child might have DLD?

Identify early signs and symptoms, such as:

Limited vocabulary by 18 months
Delayed putting words together and into sentences
Difficulty following instructions
Struggling to communicate needs and engaging in conversation
Limited use of gestures or pointing
Difficulty understanding and answering simple questions

Older children might have:

Limited use of complex sentences
Difficulty finding the right words
Difficulty understanding figurative language
Reading and literacy challenges
Disorganised storytelling and writing
Frequent grammatical and spelling errors

How Does a Speech Pathologist Help?

A speech pathologist will work with your child to:

Improve communication skills
Develop receptive and expressive language skills
Enhance vocabulary and grammar
Build confidence in communication and social pragmatic skills
Work with you to support your child at home and in other environments such as school

Our Paediatric Leichhardt therapists are skilled in assessing and diagnosing DLD, and can help your child develop essential language skills.

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