This article examines the use of like as a discourse marker and discourse particle in the spontaneous speech of children age 3-10. Data come from recorded interactions between same-sex peers. Discourse like appeared in the speech of children as young as age 4. Young children used like primarily as a discourse particle preceding determiner phrases. Like was observed in a greater number of syntactic positions as speakers’ ages increased and began to appear in different syntactic positions in approximately the order in which they developed in the language historically. Boys age 6 and younger were less likely than girls to use like and used it less frequently and in fewer syntactic positions than girls. the results suggest that boys and girls follow similar developmental trajectories but that girls become more sophisticated users of like at an earlier age than boys.