This work, first published in 1979, was a doctoral dissertation submitted to the Department of Foreign Literatures and Linguistics of the Massachusetts Institute of Technology on June 22nd 1973. The ostensible central topic of this essay is a construction which is generally known as the "pseudo-cleft" construction. This essay aims to provide an overall picture of the construction, and show why another treatment of it is necessary. This book will be of interest to those pursuing the topic of copular sentences.