Specific Language Impairment (SLI) is a disorder characterised by slow, abnormal language development.
Most children with this disorder do not present any other cognitive or neurological deficits. There
are many different pathological developmental profiles and switches from one profile to another often
occur. An alternative would be to consider SLI as a generic name covering three developmental language
disorders: developmental verbal dyspraxia, linguistic dysphasia, and pragmatic language impairment.
The underlying cause of SLI is unknown and the numerous studies on the subject suggest that there is
no single cause. We suggest that SLI is the result of an abnormal development of the language system,
occurring when more than one part of the system fails, thus blocking the system's natural compensation
mechanisms. Since compensation also hinders linguistic evaluation, one possibility for diagnosis and
remediation control is to assess basic cognitive abilities by non-linguistic means whenever possible.
Neurological plausible bases for language and language development should also be taken into account to
offer new hypotheses and research issues for future work on SLI.