The present investigation examined the characteristics of 7-year-old children attending language units in England. The study involved 242 participants who represented a randomized sample of all 7-year-old children spending 50% of more of the school week in a language unit. Results are discussed in terms of the following questions: what is the non-verbal ability of children attending language units?; do children attending language units fit the discrepancy criteria between verbal and non-verbal ability diagnostic of specific language impairment (SLI)?; and what types of language diffi culties do children with SLI attending language units have?