A wh-cleft is a grammatical construction in which a constituent is highlighted by putting focus on the end of the sentence. This is achieved by starting the sentence with a wh-clause (usually beginning with what, though other wh-words, such as who or where, are found as well): What I need is sleep (cf. I need sleep); Where I went was to the bank (cf. I went to the bank). (AEG Ch. 6)
wh-constituent
A wh-constituent is a constituent that starts with a wh-word: which book, what course, who. Recall that how is a wh-word as well, so how quickly is also a wh-constituent. (AEG Ch.2)
wh-interrogative, see information interrogative clause
