71 status of CP constituents which are introduced by a complementiser. Finite complement clauses are CPs headed either by an overt complementiser like that or if or by a null complementiser (. a null variant of that in the case of declarative complement clauses). Finite main clauses are likewise CPs headed by a C which contains an inverted auxiliary if the clause is interrogative, and an inherently null complementiser otherwise. Null C in non-finite clauses The conclusion we reached in the previous section is that all finite clauses (whether main clauses or complement clauses) are CPs headed by an.
