Approximately five percent of all children are born with the disorder known as specific language impairment (SLI). These children show a significant deficit in spoken language ability with no obvious accompanying condition such as mental retardation, neurological damage, or hearing impairment. Children with Specific Language Impairment covers all aspects of SLI, including its history, possible genetic and neurobiological origins, and clinical and educational practice. The book highlights important research strategies in the quest to find the cause of SLI and to develop methods of prevention and treatment. It also explores how knowledge of SLI may add to our understanding of language organization and development in general.

Leonard does not limit his study to English, but shows how SLI is manifested in speakers of other languages. Although his focus is on children, he also discusses adults who exhibited SLI as children, as well as parents of children with the disorder whose own language abilities became the object of study.