This paper reports on the results of a large project involving 7-year-old children attending language units in England. A group of 242 children with specific language impairment (SLI) were assessed on a battery of psychometric tests. In addition, teacher interviews were carried out to ascertain teachers' opinions of the children's difficulties. Cluster analysis revealed six robust subgroups of children with language difficulties. The findings are discussed in the context of other approaches to the classification of language impairment in children with special reference to the work of Rapin and Allen (1987).