This chapter examines the word formation patterns of the Dictionnaire’s LF. Its purpose is twofold: to provide a descriptive analysis of the patterns, and to situate them in relation to the word formation patterns of LF’s Romance lexifiers and those of pidgins. To this end, the chapter first surveys the word formation mechanisms of the main Romance lexifiers of LF and pidgins (in Sections 6.1 and 6.2, respectively). Section 6.3 describes the predominant word formation pattern attested in the Dictionnaire and provides a preliminary discussion of LF noun and verb morphology. Sections 6.4–6.8 look, respectively, at suffixation, prefixation, suppletion, compounding, and multiword lexical expressions. Section 6.9 examines how the different word formation mechanisms interact in a single functional domain, that of valency/transitivity alternations. Section 6.10 summarizes the findings and relates them to the question of LF’s taxonomic status.