Yoruba ni and si: An asymmetry in the class of prepositions

Abstract

This paper examines two grammatical elements ní and sí which have been considered as prepositions in the grammar of Yoruba (Benue-Congo). We argue that these two elements belong to different word classes; ní is a preposition, while sí is a verb. We present novel data that show syntactic asymmetries that exist between the two elements: behavior under extraction, the possibility of pseudocleft formation, the order of the phrases in a clause, iteration, formation of complex prepositions, and subcategorization. The ní-phrase acts like an adjunct phrase but this is not so with the sí-phrase. The adjunct phrase is a prepositional phrase headed by ní. It is demonstrated that the preposition constitutes a phase head in Yoruba, thus movement out of the PP is banned which explains the lack of preposition stranding with ní. The element sí, on the other hand, can be stranded. It is argued that sí is the non-initial verb in a serial verb construction.