Cleft sentences

Like fronting, a so-called 'cleft-sentence' is a technique for giving heightened prominence to an item. However, compared to fronting, a cleft sentence is a much more elaborate grammatical means, involving the division of the sentence into two clauses, each with its own verb.
There are basically two types of cleft sentences – the it-type and the wh-type (usually introduced by "what"):What we need is more time.

It-clefts consist of:
• the pronoun it
• a form of the verb be, optionally accompanied by the negation not or an adverb such as only
• the specially focused element (a noun phrase, a prepositional phrase, an adverb phrase, or an adverbial clause)
• a relative-like dependent clause introduced by that, who/which, or zero, whose last element receives normal end-focus.
The cleft sentence with "it" reverses the usual order of "given / old information – new information" by presenting the new – and important – information first.

Wh-clefts consist of:

·  a clause introduced by a wh-word, usually what, with its own point of focus, typically at its end

·  a form of the verb be

·  the specially focused element (a noun phrase or an infinitive clause)

It-clefts are relatively common in all registers but most frequent in academic prose, while wh-clefts are most frequent in conversation.