The form COMP was widely used in the classical period of Government-Binding theory in the 1980s. Since the 1990s, the simple abbreviation C has become more frequent, probably because it was widely seen as projecting a phrase CP since the late 1980s.
In languages exhibiting the Verb Second phenomenon the COMP position is the ultimate landing site of the finite verb in root clauses. Originally it was assumed that wh-phrases such as who in who did you see?, is in the COMP-position in order to explain why, in English, the presence of a wh-phrase usually excludes the presence of a complementizer (Doubly-Filled COMP filter). The standard assumption now is that COMP, or rather C'0, heads its own syntactic projection - CP - and that wh-phrases, relative pronouns and other preposed material are in the specifier position of CP.
- Chomsky, N. 1986b. Barriers, MIT Press, Cambridge, Mass.
- Lasnik, H. and M. Saito 1992. Move alpha: conditions on its application and output, MIT Press, Cambridge, Mass.
- Riemsdijk, H. van and E. Williams 1986. Introduction to the theory of grammar, MIT Press, Cambridge, Mass.