This study intends to critically examine the postcolonial interactions and the transformations of the English language in the development of Yoruba language in Nigeria. English is an important language of trade, politics, communication, and education among the bilingual and the multilingual ethnic groups in Nigeria. It is only through English language that the Hausa, Igbo, Yoruba, Efik, Tiv, Ibibio, Edo, Izon, Kanuri, and many other ethnic groups in Nigeria can discuss issues effectively among themselves. The history of the English language in Nigeria dates back to the period when Nigeria became a British colony. The postcolonial role of English and the multiplicity of Nigerian languages gave English the prominent role official language and a prominent language in the study of Yoruba language, literature, and culture. English is also a very important language in education in Nigeria. The National Policy on Education (NPE) (1977, Revised 1981, 1989, 1995, 1998, 2004) gave English a more important role in education than any Nigerian language or Yoruba language -- from the Primary level of education to the University level. French is now recognized as a second compulsory official language in education.
This paper observes that globalization has affected the number of speakers of the Yoruba language and code-mixing, code-switching, and borrowing may in future result in language shift and endangerment if our children abandon Yoruba language and opt for English.