Children in the course of lexical development frequently produce non-conventional utterances containing verbs (such as “to kill a tomato”). Most studies consider these utterances as errors, rather than approximations that demonstrate a child’s semantic flexibility and ability to use imprecise but meaningful language in order to compensate for a lack of vocabulary. In this study, we show that children with specific language impairment (SLI) produce semantic approximations more frequently than non-impaired children. This result shows that study of non conventional productions gives a new light on the lexical profiles of children with SLI and revealing their ability to compensate for lexical difficulties.