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About Specific Language Impairment (SLI)

What is SLI?

Specific Language Impairment or SLI is a type of speech, language and communication need (SLCN).

Children with SLI are usually as able and healthy as other children in all ways, with one exception; they have enormous difficulty talking and understanding language. This is their main area of difficulty.

Children with SLI are all very individual.

They may:

  • Have difficulty saying what they want to, even though they have ideas
  • Talk in sentences but be difficult to understand
  • Sound muddled; it can be difficult to follow what they are saying
  • Find it difficult to understand words and long instructions
  • Have difficulty remembering the words they want to say
  • Find it hard to join in and follow what is going on in the playground

SLI is a very broad category, with some children having mild problems that are short-lived.  Others have severe and persistent difficulties with both understanding and talking.

These difficulties are not associated with other conditions, such as cerebral palsy, hearing impairment or autistic spectrum disorders. Children with SLI are often as clever as any other child of their age but they still have difficulties with speech and language, hence the term ‘specific’, as difficulties are specific to this area.

It can be difficult to remember that they are often as able as their classmates; children with SLI often find ways of getting by such as watching and copying. Having SLI can be frustrating for children; they may develop behaviour difficulties because of this. Very often children with SLI have difficulty learning to read and spell.

What causes SLI?

There is no obvious cause of SLI. We know that the speech and language part of the brain does not develop in the right way, even though there are no other problems, and that genes play an important part in causing SLI. Unfortunately there is no medical test to see if a child has SLI or not.

How many children have SLI?

Studies have shown that in 5 year olds, SLI affects about 2 children in every classroom (about  7%). It is more common in boys than girls.

How can children with SLI be helped?

Children with SLI won’t learn language in the same way as other children, just by being spoken to and encouraged. They need language to be taught. They need to get the right support to do this so that they can learn and develop to their full potential. Without this support, SLI may cause a child lifelong difficulties.

Children with SLI will continue to need support throughout school. The type of difficulties a child with SLI has can change as they get older. For example they may get better at understanding what other people are saying but still struggle to put sentences together.

The SLI Handbook gives lots more information about SLI.

    • The SLI Handbook helps parents to understand this complicated and confusing difficulty, by describing what SLI can look like in children of all ages and how it is different from other forms of speech, language and communication needs.