The Trouble With ‘Which’ and ‘That’

By Gary Blake | August 11, 2017

In my book, The Elements of Business Writing (Pearson Education), I have a section on “Misused and Troublesome Words.” Among the most troublesome pairs of words in English are which and that. Most people use them interchangeably, but each has its special place in communication.

I wrote, “Ideally, that is used with a restrictive clause – a clause absolutely necessary to the meaning of the sentence (e.g., This is the project that will launch your career.)

Which is used with a nonrestrictive clause – a clause that is parenthetic and is not necessary to the meaning of the sentence (e.g., The executive committee, which is made up of vice-presidents, has not discussed the problem.).”

A clause is simply a group of words containing a subject and a verb.

Another writer illustrates the difference between “which” and “that” by giving us four sentences in which the adjective clause has been bracketed:

  1. Our house [that has a door and green shutters] needs painting.
  2. Our house, which has a red door and green shutters], needs painting.
  3. The classrooms [that were painted over the summer] are bright and cheerful.
  4. The classrooms, [which were painted over the summer], are bright and cheerful.

In all four cases, the adjective clause tells us something about either the house or the classrooms, but the choice of which or that changes the way we should read each sentence.

For example, in the first sentence, the use of that suggests we own more than one house and therefore must explain to you that we are talking about a particular house of ours – the one with the red door and green shutters. We cannot leave out the adjective clause because it is essential to your understanding of the sentence, that is, you wouldn’t know which one of our houses needs the paint job without the adjective clause.

The which clause in the fourth sentence is called a nonessential – or nonrestrictive clause. Since that sentence intends to tell us that ALL the classrooms were painted, the information in the adjective clause is not essential. the sentence would be clear even if the clause were omitted.

It’s my guess that about 70 percent of the time we use which we really ought to use the restrictive that. For example:

“The pen, which I gave you, is broken.”

Or, did you mean to specify: “The pen that I gave you is broken.” The word that, once again, specifies that only the pen that I gave you is broken.

By now, you can see that in the majority of cases, the word that can be left out without harming the sentence: “The pen I gave you is broken.” Without that, the idea still comes across: The [particular] pen I gave you is broken.

Many teachers refer to a clause starting with “which” as a “which clause” and should signal that the words following which may add some interesting information, but are not essential to the meaning of the sentence. To test out if you need that instead of which, read your sentence aloud and insert the phrase “the particular one” before that [ The (particular) lawsuit that was tried in South Carolina has national implications regarding the wording of reservations of rights letters. Clearly, in this case, the writer is specifying that ONLY the lawsuit tried in South Carolina is being discussed.

NOTE: This column was suggested by a reader of Claims Journal. I hope you will send me an e-mail at if there is a particular writing issue that has been disputed at your own workplace.

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About Gary Blake

Gary Blake is director of The Communication Workshop, offering claims writing webinars and seminars to claims professionals throughout the US, Bermuda, Canada, and the UK. Blake is the author of The Elements of Business Writing (Pearson Education), used at more than 100 insurance companies. He has written about claims writing for a number of industry publications. His e-mail is More from Gary Blake

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