Suggested Answers for Check Questions

Main clauses in English, although it is preferable for them to be conceptualised as CPs, are never introduced by an overt complementizer. Nevertheless, given that the clause is interpreted either as declarative or interrogative, the presence of a non-overt complementizer is justified. Finite declarative object clauses may or may not contain an overt complementizer (Peter knew (that) Mary left) in line with the assumption that they are CPs. Subordinate subject clauses, on the other hand, must contain an overt complementizer (That Mary left surprised everyone).