Yoruba, a major West African language spoken by over twelve million people, has had so much scholarly attention before the release of this 1966 work, but no extensive descriptive grammar had ever been published. Dr Ayo Bamgbose therefore made a major contribution to the study of language. This descriptive grammar derives from a large body of written and spoken texts in Standard Yoruba. In order to avoid the faulta of traditional grammars, this study has been deliberately based on a structural theory, using Halliday's Scale and Category model. Dr Bamgbose's study of Yoruba was the first full-length exemplification of this theory to be published, and will continue to be of interest to general linguists as well as to specialists in West African languages and Yoruba scholars.