Abstract

Even though diachronic change is inevitable for any living language, relatively little attention has been paid to diachronic changes in Yoruba. It remains to be seen how the earliest written documents in the language can be a source of information for how the language has evolved over a period of 200 years. In this paper, I show that Yoruba has witnessed some syntactic and phonological changes that can be accounted for through the use of the earliest written documents in the language. To account for these changes, I employ a combination of the frameworks of historical linguistics and generative linguistics. Specifically, syntactic changes are described through the formalization of Principle and Parameters, while phonological changes are described using Optimality Theory. Doing this not only ensures that the diachronic data are assessed against some current assumptions in generative linguistics but also raises questions about the nature of some aspects of natural language. For example, it is found that Yoruba had an overt Top head in the 1800s which lend support to Rizzi’s (1997) left periphery proposal. A question that becomes pertinent from the analyses offered in the paper concerns what the hierarchy is between the perfective aspect and the imperfective aspect in natural language. Using methods of historical linguistics also allows us to make a number of interesting proposals for Yoruba pre-history.