Grammar Tips: That-Clauses
  • 3-minute read
  • 20th April 2023

Grammar Tips: That-Clauses

English is full of terminology that makes it seem more complicated than it really is. A that-clause, also known as a declarative content clause, is a good example. In this post, we’ll look at it in simple terms and then in more depth.

In Simple Terms

What Is a That-Clause?

The word “that” doesn’t work on its own; it only makes sense as part of a clause. A clause is a group of words with a subject (who or what the sentence is about) and a verb (what the subject is doing).

While some clauses make sense on their own (called independent clauses), others, including that-clauses, don’t. These are called subordinate clauses.

Independent clause: I think.
Independent clause: This is a good idea.
Subordinate clause: That this is a good idea.

Although it doesn’t work on its own, a that-clause is used to connect two related ideas:

I think that this is a good idea.

In More Depth

Having grasped the basic concept of that-clauses, let’s have a look at the different ways we can use them.

With a Verb

That-clauses are commonly used with verbs for reporting or describing the mental process:

He said that it would be safe.

I think that it would be a mistake.


With a Noun

Similarly, that-clauses may be combined with nouns for opinions and feelings and for reporting nouns:

I do this in the hope that you are right.

Your statement that this would be safe was misguided.

With an Adjective

Adjectives for opinions and feelings can also be expanded with a that-clause:

I’m sure that you’ll agree this was a mistake.

As the Object of the Sentence

This is where you will most often find a that-clause in English.

Scientists have discovered that pigs can fly.

The subject of the sentence is “scientists.” “That pigs can fly” is the object.

As the Subject of the Sentence

Using a that-clause as the subject of a sentence is grammatically correct, but it’s less common because it can sound old-fashioned and formal:

That you should doubt those scientists is disappointing.

Here, the subject of the sentence is “that you should doubt those scientists.”

Because it sounds old-fashioned and overly formal to put a that-clause in the usual place for the subject – at the start of a sentence – it’s better to rewrite the sentence with a different subject or rearrange it so the that-clause subject is later:

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I’m disappointed that you should doubt those scientists.

It’s disappointing that you should doubt those scientists.


As a Complement

A that-clause is often used to introduce a complement (not “compliment”), or a word or words added to a sentence to complete its meaning. Used in this way, neither clause can stand alone:

Do you accept that you were wrong?
Do you accept?
That you were wrong.

Zero That

You can also have a that-clause without actually using the word “that.” In this case, “that” is implied. This is generally when it’s used with an adjective or a verb:

I’m sure (that) you’ll agree (that) this was a mistake.

In such cases, it may even be desirable to omit “that” to ease the flow of the sentence and make it sound more natural.

There are some instances where it cannot be omitted. This may be due to the nature of the verb:

I shouted that he was a fool.
I shouted he was a fool.
He replied that I was being mean.
He replied I was being mean.

Or it could be because it’s used with a noun:

Your statement that this would be safe was misguided.
Your statement this would be safe was misguided.


A that-clause is an important grammatical tool for adding interest and clarity to your writing. Remember:

●  It cannot stand alone.

●  When used with some verbs and adjectives, the word “that” can be left out.

●  When used with some nouns, the word “that” needs to be kept in.

If you’d like some more help with your grammar, check out our Grammar Tips section. If you’ve already written your paper, we have experts on hand 24/7 to proofread your work. You can try our services for free by uploading a sample of your work today.

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