A cleft sentence is used to connect known information with new information. This has the effect of emphasising the already-understood part.
In a cleft sentence, one message is “cleft” (cut, or divided) into two parts.
Cleft sentences are often used in conversation. They will help an English-language student sound more natural.
This is an online English grammar lesson for advanced level students.
Types of cleft sentences
1. It + be + relative clause + that/who clause
This is an it-cleft sentence.
The sentence starts “it is/was/could have been”. Next is the relative clause. The relative clause is emphasised by its placement here. The sentence ends with a that/who clause.
For example, the information is “John stole a book from the library last week”. How we present this information changes the focus. The focus is the new information, nestled within the established information.
• It was *John* who stole a book from the library last week
The new information is the subject. We already knew that a book was stolen and now we know that John is the thief.
• It was *a book* that John stole from the library last week
The new information is the object. We already knew that John took something from the library last week and now we know it was a book.
• It was *last week* that John stole a book from the library.
The new information is the time. We already knew that John stole a book from the library and now we know he carried out the theft last week.
• It was *from the library* that John stole a book last week
The new information is the place. We already knew that John stole a book last week and now we know he took it from the library.
2. What + subject + do/does/did/ + is/was + (to) infinitive
This is a wh-cleft sentence. “What” is the most common start, but you might also see “where, why, how” and so on. In a wh-cleft sentence, the first clause is usually the already-known information, and the second clause, which is the focus, introduces the new information.
For example:
• What Tom did was to hide the book under the mattress.
We knew that Tom did something – the second clause tells us that he hid the book under the mattress.
3. What happens is (that) … / What happened was (that)
This is another kind of wh-cleft sentence. In this kind of sentence, we usually know that something happened – the second, focused, clause tells us what it was or gives us further information.
For example:
• What happened was that the dog ate my homework.
We already knew that something had happened – possibly, we already knew something had happened to the homework – and the second clause tells us that the dog is to blame.
4. The reason why, the thing that, the person/people who, the place where, the day when…
This type of wh-cleft sentence is more likely to be varied in structure. Sometimes, the first clause is where you’ll find the new information.
• Why Fred and I fell out was his rudeness.
We already knew that the speaker fell out with Fred – the second clause tells us that the reason is his rudeness.
• The summer is when Kylie and I met.
We already knew that Kylie and the speaker had met - the second clause tells us that it was in the summer. The focus is the time.
• The church in the village was where my Grandad got married.
In *this* example, we already knew that the speaker’s Grandad got married – the first clause is what gives us the new information.
5. The thing/s that = What/All
This kind of cleft sentence centres around the object.
• What’s under the mattress is Tom’s book.
We knew that something was under the mattress – the second clause tells us that it is Tom’s book. The object is the focus.
• What hurt her was the falling rock.
We knew that she was hurt – the second clause tells us that the rock was the cause. The object is the focus again.
