A study investigated the effect of adult correction of grammatical errors during the language learning process. Four girls and four boys, ages 2 and 3, were interviewed individually, tape recorded and asked to repeat an adult sentence exactly. Overt mistakes were corrected either with an overt correction with expansion or with expansion only, without reference to error. Responses to corrections were categorized as entirely corrected, partially corrected, different from both the initial attempt and the correction, or refusal to correct. The results supported the expectations that (1) the children would use the correction information to repair their utterances, and (2) the ability to use adult corrections shows a developmental progression. It is concluded that, in general, children use the negative evidence in their language acquisition environments, allowing them to construct the correct grammar for their language. (MSE)