This study is based on naturalistic speech samples produced by one child learning Cree as her first language (2;01-4;03) and presents the first investigation into the development of preverbs in the language. Preverbs are an optional class of morpheme which precede the lexical verb stem, dividing into grammatical, lexical and directional (deictic) subclasses. Of nine preverb types in the child's inventory, 47/48 tokens are grammatical. We argue that these appear early because they exhibit phonological transparency (do not alternate in form) and positional predictability (are restricted to preverb position). Lexical and directional preverbs, however, alternate in form and may appear in either preverb position or within the lexical stem. Furthermore, the child first began to use preverbs with the grammatically simpler independent (default) inflection (2;04), and 7 months later with the more syntactically restrictive conjunct inflection (2;11). She also used each preverb with one inflection type only, even where a choice of inflections was available, and she never produced more than one preverb per verb complex although multiple preverbs are common. In sum, grammatical complexity appears to be a driving factor in determining the child's development pattern.