Children generate novel utterances from the outset of multiword speech. In this study, we apply a usage-based method called 'traceback' to the multiword utterances of four two-year-olds to see how closely related these utterances are to their previous utterances. Data was collected from the age of 2;0 until 6 weeks later on a relatively dense sampling schedule. We attempted to match each novel multiword utterance in a two-hour corpus to lexical strings and schemas that the child had said before. Matches were found for between 78-92 percent of all multiword utterances. Between 62-91 percent of the slots in schemas created by these tracebacks were for referring expressions and were filled with nouns or noun phrases. For one child, recording continued throughout his third year and we compared his data at MLUs matched with the other three children to investigate developmental changes. We found that, with increasing MLU, and developmentally, children were less repetitive within sessions, the tracebacks required a wider range of semantic slots and the material placed in these slots increased in complexity. © 2009 by Walter de Gruyter GmbH.