You would’ve seen noun phrases as appositive, like in these sentences:
Inception, my favorite movie, was directed by Christopher Nolan.
Our teacher Ms. Thompson is organizing a field trip.
But noun clauses too can be appositive. Such clauses, which can be finite or non-finite, are called appositive clauses or appositive noun clauses. Some grammar books though call them noun complement clauses.
1. Finite clause as appositive
Although we usually study noun clause as one broad unit, they can be divided into three types:
- That-clause, which are introduced by that
- Wh-interrogative clause, which are introduced by wh-elements (how, when, where, why, who, whom, whose, what, and which)
- Yes–no interrogative clause, which are introduced by if and whether
Of these, noun clauses introduced by that, wh-elements, and whether can function as appositive, with that-clause being the most common.
1.1. That-clause as appositive
That-clause works as appositive with few nouns, mainly reporting nouns, such as:
admission, announcement, answer, argument, assertion, assumption, belief, claim, comment, declaration, excuse, explanation, fact, idea, message, news, observation, possibility, proposal, proposition, proof, recommendation, remark, reply, report, response, saying, statement, story, suggestion
As appositive, that-clause can be restrictive or non-restrictive. (This is not a relative clause introduced by that, which can only be restrictive.) Examples:
The rumor that she is quitting her job is false.
The idea that they could get away with shortcut was foolish.
The news that they were getting married didn’t surprise anyone.
The fact that she is the youngest CEO in company’s history has inspired many.
Government’s promise that it is doing everything possible to bring back people caught in the war zone was reassuring.
Their hope that a passing ship would find us faded with each passing day.
The company’s claim, that the vaccine has been tested on the local population, failed to reassure people.
[It has been marked non-restrictive on the assumption that we already know what company’s claim is. There is absolutely nothing in the sentence itself that signals non-restrictiveness]
Test to check if the clause is indeed an appositive
Since an appositive is a restatement of the preceding noun phrase, the noun phrase should be same as the appositive. For example, in the sentence Our teacher Ms. Thompson is organizing a field trip, where Ms. Thompson is appositive, we can say:
Our teacher is Ms. Thompson.
If we do the same with the first example, we get:
The rumor is that she is quitting her job.
If it was not an appositive, we would’ve got a weird result. Try applying this to The rumor that first spread in her office is false. More on this later in the post.
This test BTW holds for all appositive clauses, finite or non-finite.
1.2. Wh-clause and whether-clause as appositive
As appositive, these clauses can only be non-restrictive. Examples:
The question, what caused the power outage, was investigated thoroughly.
The mystery, how the magician performed the trick, intrigued everyone.
The dilemma, whether she should stay or leave, troubled her.
1.3. We’re not done with finite clause yet
If you’re an intermediate to advanced learner, you would’ve been exposed to the three types of noun clauses we covered earlier. But if you’re an advanced plus learner, if there is such a term, you would know that there are two more – exclamative clause and nominal relative clause. Since they too function nominally, in common use, they are lumped together with the three we’ve covered so far under one big umbrella of noun clause. Of exclamative clause and nominal relative clause, only the latter can function as appositive. Examples:
The rule, whatever was agreed upon, must be followed.
The winner, whoever finished the race first, would get a trophy.
The recipient, whomever the jury decided, deserved the honor.
1.4. Appositive clause vs. relative clause
Appositive clauses introduced by that can be easily confused with relative clauses introduced by that: They both follow a noun phrase and, of course, both are introduced by that.
Earlier astronomers put forth the idea that earth was the center of universe.
Earlier astronomers used telescopes that couldn’t tell much about the universe.
Earlier astronomers used telescopes that a layperson couldn’t use at all.
How do you tell if the underlined clause is an appositive or a relative clause?
There are few differences between the two.
1. Appositive clause is, well, appositive; the other is not.
Let’s apply the appositive test we covered earlier to the above three sentences.
The idea is that earth was the center of universe. [This makes sense]
Telescopes is that couldn’t tell much about the universe. [This doesn’t make sense]
Telescopes is that a layperson couldn’t use at all. [This too doesn’t make sense]
Since only the first makes sense, only the first sentence contains an appositive clause.
2. That is not a clause constituent in appositive clause; it is in the other.
That, being a conjunction (or particle), is not a clause constituent in appositive clause and hence is not required for the clause to make a meaningful sentence. In the first example, earth was the center of universe doesn’t require that to form a meaningful sentence.
However, that is a clause constituent in relative clauses and hence is required for the clause to make a meaningful sentence. In the second example, that (= telescopes) is the subject of the clause and is required to convert the clause into a meaningful sentence: Telescopes couldn’t tell much about the universe. In the third, that (= telescopes) is the object of the clause and is required to convert the clause into a meaningful sentence: A layperson couldn’t use telescopes at all.
3. In relative clause, that can be replaced by which; it can’t be in the other.
Replace that by which in each clause. If the sentence still makes sense, the clause is a relative clause. This works because in relative clause, we’re replacing pronoun that with pronoun which, but in appositive clause, we’re replacing a conjunction (or particle) with a pronoun. (See point #2.) Let’s replace and see what we get.
Earlier astronomers put forth the idea which earth was the center of universe. [This doesn’t make sense]
Earlier astronomers used telescopes which couldn’t tell much about the universe. [This is still fine]
Earlier astronomers used telescopes which a layperson couldn’t use at all. [This too is fine]
Since the last two sentences still make sense, the clauses contained in them are relative clauses.
4. Appositive clause can follow only few nouns; the other can follow almost any.
An appositive clause follows limited set of nouns (we covered few earlier). A relative clause though can follow almost any noun.
Finite clauses as appositive finally end. Here is a summary:
| Type of finite nominal clause | Does it function as appositive? |
| That-clause | Y |
| Wh-interrogative clause | Y |
| Yes–no interrogative clause (If) | N |
| Yes–no interrogative clause (Whether) | Y |
| Exclamative clause | N |
| Nominal relative clause | Y |
Note: For a finite clause that has multiple introductory words, some introductory words may not lead to natural and idiomatic subject.
2. Non-finite clause as appositive
There are two types of nominal non-finite clauses:
- Nominal to-infinitive clause (also called infinitive phrase)
- Nominal -ing clause (also called gerund phrase)
Both can function as appositive in a sentence. Examples:
My hobby, collecting vintage stamps, requires patience and networking.
The company’s primary goal, reducing carbon emissions, aligns with global environmental efforts.
The team’s single-minded goal, to win the World Cup, drove them to train maniacally.
The company’s focus, to increase market share, led to several missteps.
Besides, we have a variant of nominal to-infinitive clause, derived from the finite clauses we covered earlier:
- infinitive wh-clause derived from wh-interrogative clause
- infinitive whether-clause derived from yes–no interrogative clause
(Note that if and that can’t introduce a to-infinitive clause.)
They function much like their parental clauses, though with some restrictions. Examples:
The question, whether to invest in the stock, needed careful consideration.
His main concern, how to manage the team effectively, was discussed at length.
The next big challenge, where to drive growth, was discussed threadbare in the board meeting.
Here is a summary of non-finite clause as appositive:
| Type of non-finite nominal clause | Does it function as appositive? |
| To-infinitive clause | Y |
| Infinitive wh-clause | Y |
| Infinitive whether-clause | Y |
| -ing clause | Y |
Note: For a non-finite clause that has multiple introductory words, some introductory words may not lead to natural and idiomatic subject.
