How to distinguish it-cleft and extraposition? 'It was Ben that found it' v 'It was clear that Ben found it'

Question

I have a question about it-cleft and extraposition. For example the two sentences:

1. It was in the apartment that Ben found something interesting -- a mouse eating cheese.
2. It was obvious that whenever the cake was done, my brother wouldn't eat it unless his father came home.

I am confused about how to identify these two variants. Does it relate to the function of the phrases? Thank you!

Answer 1

1. It is clear [that Ben ate the cheese]. ^{(extraposition)}
2. It is Ben [that ate the cheese]. ^(it-cleft)

The examples above look very similar. They both have a meaningless dummy pronoun, it, as Subject, and they both have similar looking clauses that appear at the end of the sentence. However, although similar, they are not the same.

Extrapositions

We don't like to use clauses as Subjects, because they are difficult for listeners to process. These examples are grammatical, but they're clunky:

• [That Ben ate the cheese] is clear.
• [To hang out with you friends] is nice.
• [Whether the chicken got to the other side] is not known.

The extraposition construction is a way of making the sentence more fluid and easier to process. This construction simply puts a meaningless dummy it, in the Subject position and shunts the clause down to the end of the sentence where it's easier to process:

3. It's clear [(that) Ben ate the cheese].
4. It's nice [to hang out with your friends].
5. It is not known [whether the chicken got to the other side].

It-clefts

It-clefts break a sentence into two parts. They foreground, or put into focus, one particular phrase and they 'background' the rest of the sentence.

They are called it-clefts because they use the pronoun it as a meaningless dummy subject of the verb be. They are 'clefts' because the rest of the sentence is cleft into two parts, where one appears as the complement of the verb be and the rest of the sentence appears as a relative clause at the end of the sentence.

Compare the following:

6. Boris danced naked.
7. It was [Boris] [that [danced naked]].

In (7) the word Boris no longer appears as the Subject. Instead it appears as the Complement of was. This word is now the focus of the sentence and is more prominent than it is in (6). Here, that danced naked is less prominent. It might already have been mentioned in the previous conversation. It definitely is not new news to everybody that someone danced naked here.

Notice, also, that the relative clause after the word that has a gap in it where the Subject would normally be:

8. It was Boris that [danced naked.]

This gap corresponds with (it is co-indexed with) the phrase after the verb be:

9. It was Boris that [Boris danced naked]
10. It was Boris_i that [___i danced naked]

The phrase after the verb be is often contrastive in flavour. You might well understand this sentence to mean something like:

10. It was Boris (not Matt, or someone else) who danced naked.

Tests to tell extrapositions from it-clefts

In the following section [ * ] indicates that the example is ungrammatical.

Firstly, you can always replace a Subject it in an extraposition construction with the clause at the end of the sentence:

11. It is clear [that Ben ate the cheese]. ^{(extraposition)}

12. [That Ben ate the cheese] is clear.

13. It is Ben [that ate the cheese].^(it-cleft)

14. *[That ate the cheese] is Ben.

Secondly, if the clause at the end of the sentence is a non-finite clause (it doesn't have a tensed verb), then it is an extraposition, not an it-cleft:

15. It is not unusual [to see Boris dance naked]. ^{(no tensed verb-->extraposition)}

Third, if the clause at the end of the sentence is an interrogative clause, it is an extraposition, not an it-cleft:

16. It is not clear [whether Rishi danced naked] ^{(interrogative whether-->extraposition)}

Fourth, if the clause at the end of an extraposition is a tensed declarative clause, then you can always omit the word that:

17. It is clear that Ben ate the cheese. ^{(extraposition)}

18. It is clear Ben ate the cheese.

19. It was Ben that ate the cheese. ^(it-cleft)

20. *It was Ben ate the cheese. ^{ungrammatical in standard English}

Fifth, a declarative, tensed clause at the end of an extraposition (excluding the word that, if present) will always be a well-formed clause, which could stand as a sentence in its own right:

19. It is clear that [Ben ate the cheese]. ^{(extraposition)}

20. Ben ate the cheese.

21. It is Ben that [ate the cheese]. ^it-cleft

22. *Ate the cheese.

Sixth, the word that in an extraposition cannot be replaced by a wh-word such as who or which. In an it-cleft it often can be:

23. It is clear that Ben ate the cheese. ^{(extraposition)}

24. *It is clear who Ben ate the cheese.

25. It was Ben that ate the cheese. ^it-cleft

26. It was Ben who ate the cheese.

Seventh, an it-cleft has a relative clause with a gap in it at the end of the sentence. The gap is co-indexed with the complement of the verb. be, as discussed further above. If you take the relative clause and plug it with the complement of the verb be, you should get a well-formed sentence:

27. It was [Ben] that [ __ ate the cheese] ^it-cleft
28. [Ben] ate the cheese.

There is no gap in the clause at the end of an extraposition, so you can't fill it with the other phrase. But if you try to squish the two together regardless the result is usually ungrammatical:

29. It was [clear] that [Ben ate the cheese].
30. *Clear Ben ate the cheese.
31. *Ben ate the cheese clear.

The Original Poster's examples

32. It was in the apartment [that Ben found something interesting -- a mouse eating cheese].

33. It was obvious [that whenever the cake was done, my brother wouldn't eat it unless his father came home].

The easiest test we can do here is to see whether we can replace the dummy subject it with the that-clause that appears at the end of the examples, without changing the meaning:

34. [That Ben found something interesting -- a mouse eating cheese] was in the apartment.

This is nonsense and so shows that (32) is an it-cleft and not an extraposition. Let's see what happens to (33):

35. [That, whenever the cake was done, my brother wouldn't eat it unless his father came home] was obvious.

This is certainly very ugly and ungraceful (which is why we have extrapositions in the first place), but it is grammatical. Of course, the longer the subject clause, the more ungraceful such a sentence will be.

Let's try the omitting that test:

36 It was obvious, whenever the cake was done, my brother wouldn't eat it unless his father came home.

That seems as good as the original sentence, and suggests it is an extraposition. Lastly, let's try the fifth test. If this is an extraposition, the clause after the word that should be able to work as a stand-alone sentence:

37. Whenever the cake was done, my brother wouldn't eat it unless his father came home.

This seems to clinch it. This works fine and strongly suggests that the original sentence is an extraposition.

Answer 2

The phrase immediately after 'be' in the cleft construction is always related to a position inside the that-clause:

1. It was in the apartment that Ben found something interesting. -> Ben found something interesting in the apartment.
2. It was Sam that won the race. -> Sam won the race.
3. It was the garage that the storm destroyed. -> The storm destroyed the garage.

This is never the case in the extraposition structure: (I'll keep your terminology here, but it's likely that this is not really a case of extraposition in the sense that the term is used in other contexts.)

1. It was obvious that Sam was mad. -> * Sam was mad obvious.
2. It was unfortunate that the storm destroyed the garage. -> * The storm destroyed the garage unfortunate.

As a consequence of this fact, cleft constructions allow wh-phrases instead of the complementizer 'that':

1. It was Sam who won the race.
2. It was the garage which was destroyed by the storm.

Extraposition doesn't allow this

1. *It was obvious who Sam was mad.
2. *It was unfortunate which the storm destroyed the garage.

In the extraposition structure, the clause can replace the 'it' pronoun in subject position:

1. It was obvious that Sam was mad. -> That Sam was mad was obvious.
2. It was unfortunate that the storm destroyed the garage. -> That the storm destroyed the garage was unfortunate.

This is not possible in the cleft construction:

1. It was in the apartment that Ben found something interesting. -> * That Ben found something interesting was in the apartment.
2. It was Sam that won the race. -> * That won the race was Sam.
3. It was the garage that the storm destroyed. -> * That the storm destroyed was the garage.

Answer 3

Let's start with simpler examples, so the differences stand out. The easiest difference to spot between the two rules is that Extraposition inserts one dummy word, while It-cleft inserts three. I'll boldface the inserted words below.

1. Extraposition:
   It was obvious [that the cake was done].
   comes from
   [That the cake was done] was obvious.
   Extraposition moves the heavy subject clause [that the cake was done] to the end, leaving dummy it behind to serve as Subject.

2. It-Cleft:
   It was [in the apartment] that [Ben found them].
   comes from
   [Ben found them] [in the apartment].
   Cleavage breaks the sentence up into two phrases, bracketed above, and emphasizes one of them by using it as the predicate of a clause with it as subject and is or was as an auxiliary, followed by a relative clause containing the other (de-emphasized) phrase. The it, the be form, and the that complementizer are all inserted by the rule.

The English Extraposition transformation simplifies structure; heavy clauses are easier to understand when they come at the end instead of the beginning of sentences, because English is right-branching.

But all English cleft transformations (there are several other kinds besides It-clefts and Wh-clefts) create structure, and thereby make parsing harder. One way to emphasize something is to make it harder to understand -- if people work to understand it, they'll remember it, goes this theory. Speaking as a teacher, I'm not so sure it's correct.

Answer 4

It cleft:

The simple form of the sentence is

Ben found something interesting in the apartment -- a mouse eating cheese.

In order to create an “it cleft”, some movement of the elements is required and “it was/is, etc.”, is placed at the start:

It was in the apartment [that] Ben found something interesting -- a mouse eating cheese.

The website for eCampus Ontario is helpful.

Extra position

Extra position takes place when a relative clause, content clause, adjunct, etc. is moved from its normal position in the sentence, i.e. next to the word it qualifies. Sometimes this is not idiomatic, sometimes it is necessary:

From Wiki: https://en.wikipedia.org/wiki/Extraposition#Examples

a. Someone whom we don't know left a message.

b. Someone left a message whom we don't know. - Extraposition of relative clause out of subject

a. Susan said something that nobody expected more than once.

b. Susan said something more than once that nobody expected. - Extraposition of relative clause out of object

a. Some guy with red hair was there.

b. Some guy was there with red hair. - Extraposition of prepositional phrase out of subject

a. How frustrated with their kids are they?

b. How frustrated are they with their kids? - Extraposition of prepositional phrase from predicative adjective phrase

a. %What that was so entertaining actually happened?

b. What actually happened that was so entertaining? - Extraposition of content clause from subject wh-element

a. %What that upset everyone do you think they did?

b. What do you think they did that upset everyone? - Extraposition of content clause from object wh-element