top of page



Developmental language impairments

Learning to understand and use language is very complex. Most children are pre-wired to learn language from birth. Given the right environment and sufficient stimulation, most children learn to understand and use language. However, there is a huge population of children for whom language learning is enormously challenging.

What is a language disorder?

Almost all of the world's children learn language in the first 5 years of life, and continue to learn more language as they develop through childhood into the teenage years. This is what is referred to as 'language acquisition'. However, speech-language therapists work with the 5% to 7% of children who do NOT acquire language easily. Recently, an international group of researchers has agreed on the term 'language disorder' to refer to the set of language difficulties or impairments that children can have that create obstacles in their lives, and that we know, from previous research, do not resolve by themselves. (I do not like the word 'disorder because I do not like medicalising impairments, but that is my bias). Some people call the language problems that children present with 'aphasia'. However, usually 'aphasia' is a word that is usually only used to refer to the loss of language that has already developed (e.g. when a person loses their ability to understand and/or express language following a stroke).

A language impairment can be receptive, expressive, or a combination of both.

  • A 'receptive language problem' or  a 'verbal comprehension problem' occurs when a child has difficulty understanding language.

  • An expressive language problem occurs when the child has difficulty expressing himself or herself.

  • Some children have a language delay that involves both expressive and receptive difficulties.

What’s the difference between speech and language?


Speech refers to the sounds that we make that communicate meaning. Speech is a physical activity

that is controlled by the brain. Speech requires coordinated and  precise movements of the tongue,

lips, jaw, palate, lungs and larynx.  


Language is made up of words and sentences, and the various ways in which sounds, words and

sentences are used to communicate.


Often, but not always, children who have language learning problems also have difficulties with

producing the sounds of speech.

What causes children to have language learning impairments?
 1. Expected language impairments

We know that language learning problems are associated with certain conditions. In other words,

we can be pretty sure that almost all children who come to us with these conditions will have some degree of speech, language, and/or hearing problem. When children who live with these conditions have a language impairment, we describe the language disorder as  "A language disorder associated with X" (e.g. Down Syndrome/ Autism etc).


  • A hearing loss

  • Cerebral palsy

  • A strong genetic history of language delay

  • Seizure disorders (epilepsy)

  • Family history of language disorders

  • Family history of learning difficulties

  • Prematurity

  • Very low birth-weight

  • Failure to thrive

  • Tumours

  • Strokes

  • Illnesses that affect the brain e.g. meningitis or encephalitis

  • Autism

  • Intellectual disabilities (including Fragile X, Down Syndrome)

  • Fetal alcohol syndrome

  • Brain injury due to car accidents

  • Brain injury due to cancer treatment

  • Long term illness and hospitalisation

  • Adoption

2. Language impairments with no apparent origin

However,  for many children, language learning is a problem for unknown reasons.  Sometimes  we simply do not know why a child has difficulty. When we do not know why the child has a problem with learning to understand and/or to use language, we usually take a team approach and so we refer to other team members such as developmental paediatricians, psychiatrists, neurologists, occupational therapists, physiotherapists, psychologists and others to work towards finding the reason/s and to determine what is commonly referred to as the 'diagnosis'.

What is a 'developmental language disorder'?

In 2016 and again recently, an international group of leading researchers has agreed on the term 'DLD' or "developmental language disorder". This is a specific label given to a specific group of problems which are not associated with:

autism spectrum disorder (ASD)
language difficulties acquired after brain injury (e.g. TBI, brain surgery, brain tumour)
acquired epileptic aphasia in childhood
certain neurodegenerative conditions
genetic conditions such as Down syndrome

cerebral palsy
oral language difficulties associated with sensori-neural hearing loss

DLD can be associated with

having a family history of DLD
being male
living in poverty
low level of parental education
experiencing neglect or abuse
experiencing problems around or before time of birth

DLD can co-occur with conditions such as impairments in

Attention (e.g., ADHD)

Motor (e.g., dyspraxia, dysarthria)

Executive function
Adaptive behaviour
Behaviour problems
Auditory processing (e.g., APD)
Intellectual disability

Here is a video of Prof Dorothy Bishop explaining DLD. In this film Dorothy Bishop explains the consensus process, the agreement to use the term Developmental Language Disorder (DLD) and the agreed criteria for this disorder.

What is a 'specific language disorder/impairment' ?

This is the old fashioned term for a set of language impairments of unknown origin. It was a diagnosis given to children with language development but of no known origin, with no co existing conditions. This was problematic because many children with language problems do have associated problems and these children were ruled out from getting help for their language problem because they could not be diagnosed as SLI. You may want to read the editorial to an international journal issue on the debate here:

When do language impairments become apparent?

We can determine that a child is not learning to understand and/or use language from a very, very young age – under 15 months of age, even in the first year of life. Sometimes, though, the developmental problems are not all that clear until the child is a little older. (We do not wait - if we think there is a problem, we attend to it as early as possible. We do not wait for the child to grow out of it - they may not).


Do language impaired children ‘catch up'?

Yes and no.

It all depends on what the cause of the language learning problem is, and what opportunities they have to learn and be supported in their learning.

Many children who start to talk later than most other children do catch up all on their own, in their own time. However, we have ample evidence that a good proportion of late talkers land up with difficulties with later language development (such as the language learning that is necessary for school). In addition, there has been research that has shown that half to almost all children who are diagnosed with DLD remain language impaired throughout life. Many children with DLD, with speech therapy as well as academic support, do well, but they are at risk of academic problems, emotional problems and social problems. Later on, their employment prospects are poor. It sounds terribly gloomy, but this is the reality of what the research shows.

Is speech-language therapy effective for children with language impairments?

We have over 30 years of hard evidence that

  • Early intervention (starting under 3 years of age) with children who show signs of language delay works best;

  • Speech-language therapy is effective with children who have language impairments. 'Effective' does not always mean that the individual will be "cured", but that improvement in the language skills and all aspects of function related to the language impairment can occur.


What do we mean by "language"?


All languages have their own rules for the use of sounds. When children first start to speak, they muddle up their sounds, but quickly learn the sound system of their language. 

When children do not learn the sound system of their home language, they 'muddle' up sounds for much longer, or use ways of muddling up sounds that we do not see in typically developing children. For example, they make the sounds produced at the back that should be made in the front of the mouth (e.g. tun for sun; too for shoe), or the other way around (e.g. koo for two; gake for take). They might 'reduce the clusters' (e.g. bown for brown; goo for glue; top for stop). They might make long words short (e.g. amu for animal; tephone for telephone); they might make voiced sounds voiceless  (e.g. so that d becomes t, and g becomes k); they might even combine processes such as making back sounds in the front and then make them voiceless instead of voiced (e.g. g becomes d which becomes t, so the child says "tate for gate"). There are many  other 'phonological processes' that children use. We have special ways of approaching phonological problems to help children to sort out their systems. (Click here for more information)



These are the tiny ‘bits’ that we use to change the meaning of words. For example, we add ‘-s’ to make a plural (the boys, the cats); we add ‘-ing’ such as the "boy  is  singing"; we add ‘–ed’ to make a past tense (e,g the dog walked; he jumped). Some languages have incredibly complex morphology such as African languages. Children have to learn these rules.


Vocabulary (Semantics)

Vocabulary refers to the words that we use to express meaning. There are thousands of words that we need to learn. We need memory as well as a good 'filing system'. We hear a word and 'file' it in our 'lexicon', the filing system of words in our brains. We file words in many ways - what does the word mean? what does it sound like? how many syllables are in the word? what is the word similar to? what does the word rhyme with? what does the word end with? is it a swear word? is it a technical word? is it a word used often?

Children learn words very quickly, and although the ability to learn new words diminishes over time, we are always able to learn new words if our lexicon is strong.

  • Many children that we see have difficulty learning new words.

  • Some have difficulty remembering words

  • Some cannot retrieve the words that they want - we call this a 'word-finding problem'.


Sentences (Grammar)

We learn to put the words that we have learned into sentences, made up of  phrases and clauses We have a pretty good idea of the stages of development of grammar in the languages that have been studied (such as English), but we still do not enough about the development of grammar in many languages (especially the South African indigenous languages).

Language-impaired children often have difficulty learning to understand and/or use the grammar rules of their language. For example, we would not expect a five-year-old child to say "Me want go up" or "Thems the boys what did catch us", but we might accept that grammar from a younger child.


This language skill enables us to tell stories, describe events, have conversations, tell jokes and create poems or lyrics, and to use language in different ways for different purposes such as to argue, negotiate, discuss and debate.

Some children have difficulties with telling us a story; in telling us about something that happened; in telling us how to proceed to do something and so on. Learning to produce different discourse types happens throughout childhood.

The rules of social language (Pragmatics)

This set of skills enables us to use language. For example, we need to be able to tell if our listener has understood what we have said, and if not, to re-word what we have said, We need to know how to talk to a school principal versus a classmate. We need to know about non-verbal communication such as eye contact.

It is never too early to consult a speech therapist. We are trained to work with children from the day that they are born.

We call therapy that starts when children are very young "early intervention".

We have decades of research that shows that the earlier that we start to intervene when there is a delay, the better the outcomes.

Some researchers estimate that

6 to 8% of all children have significant difficulty learning to understand and/or use language

risk list

Finding a diagnosis is sometimes not as important as one thinks. Click here to go to a page on which I discuss diagnosis

bottom of page