When To Use ‘That’ And When To Use ‘Which’

When To Use ‘That’ And When To Use ‘Which’


Rule of thumb

If the part of the sentence after ‘which’ or ‘that’ gives specific, identifying information and removing it will change the meaning of the first part of the sentence, use ‘that’. In all other cases, use ‘which’.

Two sentences

The best way to explain the rule is to use an example. Look at these two sentences:

  1. Our office, which is in Cape Town, is eco-friendly.
  2. Our office that is in Cape Town is eco-friendly.

Which. In the first sentence, we have one office that is eco-friendly. It happens to be in Cape Town. The part of the sentence that says ‘which is in Cape Town’ is additional information. It’s called a non-restrictive clause. Because it doesn’t restrict the rest of the sentence, removing it won’t change the basic meaning of the sentence, which is that our only office is eco-friendly.

That. Changing ‘which’ to ‘that’ in the second sentence changes the meaning of the sentence. Now, we have more than one office. One of our offices is eco-friendly. To identify which one it is, I tell you that it’s the one in Cape Town that’s eco-friendly, implying that the other offices aren’t. The part of the sentence that says ‘that is in Cape Town’ is not additional information. It’s specific, identifying information. This specific, identifying information is called a restrictive clause. Because it restricts the rest of the sentence, removing this information would change the meaning of the sentence. You wouldn’t know to which office I’m referring.

Exercise 1

  1. A water leak has damaged our reception area that was redecorated in December.
  2. A water leak has damaged our reception area, which was redecorated in December.
The correct answer: sentence 2. There is only one reception area, so there is no need to use ‘that’ as a restrictive clause to identify which reception area is being discussed.

Exercise 2

  1. The company that haggled over its contract with our company the most is now our biggest client.
  2. The company, which haggled over its contract with our company the most, is now our biggest client.

The correct answer: sentence 1. The words ‘the most’ tell you that there are other clients that have also haggled over the contract. The restrictive clause beginning with ‘that’ provides specific, identifying information, so that you know which client is being discussed.

Punctuating all this

When you use a non-restrictive clause with the word ‘which’, you set that part of the sentence off between commas, like this:

The contract, (comma) which states that late delivery will be fined, (comma) will be signed today.

When you use a restrictive clause with the word ‘that’, you don’t need any commas:

The contract that states that late delivery will be fined will be signed today.

Good luck!

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This article has 8 comments

  1. Victory Crayne

    I suggest using ‘That’ in all cases. English is a
    language that is evolving and many common folks
    who use it use ‘that’ in all cases. They don’t
    care about “restrictive” or “non-restrictive”
    clauses. Heck, they don’t even know what a clause
    is. At least use ‘that’ in dialogue, unless the
    speaker is a teacher or English or a professor.
    Those poor people are stuck in the old ways of doing things.

    Victory Crayne, writer

    At 08:51 AM 5/11/2015, you wrote:

  2. Peter Chabanowich

    Thank you for this post – very instructive, clearly described and cogent.

  3. shantanu

    Thank you. This was very useful information. Keep bringing some more alike. 🙂

  4. Rosalia

    Thanks so informative

  5. Stan Carey

    There’s no grammatical basis for this rule. It’s a style preference, observed by some writers and editors but not by others. ‘Which’ can be restrictive too, and often is, and indeed has been so in fine writing for centuries. It’s the comma that does the real work here. I’ve written about this in greater detail here: http://stancarey.wordpress.com/2011/10/18/that-which-is-restrictive/

  6. D N Prahlad

    A wonderful compact lovely lesson. Similar ones are welcome. can v/s may will provide a lot of fodder.

  7. R Fowler

    I would say “Our Cape Town office is eco-friendly”. This implies there is more than one and does more with less words than suggested. Just a thought!

  8. Peter Chabanowich

    …and that which we must not contemplate. . .

Comments are now closed.