Full text can be accessed at http://www.tandfonline.com/doi/abs/10.1080/02572117.2004.10587238The article discusses the problem of analysis of the element na in Chathu (Pare), a Bantu language of Tanzania. This element functions both as a preposition with a range of meanings and as a conjunction. A similar element with the same problem of analysis exists in most Bantu languages, and, in fact, the phenomenon of a word meaning both ‘and’ and ‘with’ is extremely common in other African languages as well. The article presents an overview of the semantics of na and proposes the most likely tines of semantic development that link the various meaning senses. After a discussion of the agreement phenomena when na is used in the conjunctive meaning, the conclusion is reached that na is a preposition in alt of its uses. A certain degree of grammaticalization has occurred in the possessive use of na.