this paper. We thank Michal Biran, Mali Gil, Aviah Gvion, and Dafna Wenkert-Olenik for their help in discussions and testing, and the participants for their patient participation. Address correspondence to Naama Friedmann, School of Education, Tel Aviv University, Tel Aviv 69978, Israel. E-mail: naamafr@post.tau.ac.il, http://www.tau.ac.il/~naamafr

The majority of studies in children’s acquisition of syntax have focused on production. However, research suggests that infants understand more about their language than they are themselves producing. The current work focused on one aspect of early syntax, the inflectional marker, –s, which functions both as a plural nominal inflection and the 3 ii rd person singular verbal inflection, in the receptive domain. The properties of the use of such inflectional markers by young children have generated a great deal of theoretical interest in the production literature. Experiments 1 and 2 tested 19-month-olds ’ sensitivity to this marker in singular, plural, and ungrammatical contexts, using the Headturn Preference Procedure. These infants preferred listening to grammatical passages when compared with uninflected ungrammatical passages, but showed no preference when compared with doubly inflected ungrammatical passages. This finding contradicts those in the productive domain, in which young children are much more likely to produce errors of omission than