That vs. which . . . oh the humanity

This week, I edited a lengthy article written by a fairly experienced author. The article was well written, but (isn’t there always a but) there was one problem . . . that and which were used incorrectly in most sentences. This is hardly surprising; in my experience knowing when to use that and when to use which is one of the most confusing usage issues.

The reason for the confusion? Those who try to explain the use of these relative pronouns invariably launch into an explanation using words such as relative pronouns, subordinate clauses, restrictive clauses and nonrestrictive clauses. If you’re not asleep after this explanation, then you’re more confused than ever.

I am now going to explain the use of which and that without using any of these sedating, bewildering terms. But I warn you, this is a tough one. Keep your wits about you . . .

That and which are pronouns used to introduce clauses in a sentence. Their use allows writers to combine sentences and avoid choppy prose. For example:

Our customers were confused by the instructions. They were not written very clearly.
The instructions, which were not written very clearly, confused our customers.

The article was clearly plagiarized. It was removed from the publication.
The article that was clearly plagiarized was removed from the publication.

The confusion sets in when it comes to deciding which pronoun to use — that or which. They are not interchangeable. And they should certainly never be mixed for the sake of word variation.

One way of deciding whether to use that or which is to determine if the clause in question can be omitted without changing the meaning of the sentence. If the clause can be omitted, use which. If the clause cannot be omitted, use that.

The article that was clearly plagiarized was removed from the publication.

That is used in this sentence because that was clearly plagiarized tells the reader which article was removed. The one that was plagiarized.

The instructions, which were not written very clearly, confused our customers.

Which is used in this sentence because you can remove the clause which were not written very clearly without changing the meaning of the sentence.

Another way to remember which word to use — always use that unless you could justifiably place a comma before the clause. Which always mandates the use of a comma.

The fact that he could not write, which was apparent to anyone who read his work, seemed to escape him.

You need a comma after the word write, so use which.

This is all seems fairly straightforward. However, many writers (myself included) are often confused when it comes to deciding if a clause is necessary or not. This is most likely the result of over-thinking. (Over-thinking . . . hmmm.) But that’s an issue we can tackle in another post.

A version of this article also appeared on Ragan Communication’s PR Daily.

5 Responses to “That vs. which . . . oh the humanity”

  1. [...] version of this story first appeared on the author’s blog Impertinent Remarks. [...]

  2. What stumps me at times is when to use that vs. who. Any tips?

    • laurajane says:

      For that versus who, the quick rule of thumb is to use “who” if you were talking about a person and “that” if you were referring to anything else. But of course there are exceptions. Perhaps that’s a topic for my next blog. Stay tuned!

    • laurajane says:

      That vs. which — I think the general rule of thumb is to use “who” when referring to person and “that” when referring to anything else.

  3. Marti Cuatt says:

    This must be the clearest explanation of how to use which and that I’ve ever read. Which/that is one of those things that I’m constantly amending in writing I edit, but if I was ever asked to explain how they should be used correctly, I’d be stumped. I just know how to use the two.

    In future I’ll point whoever may ask the question to your blog post.

    • laurajane says:

      Thanks. I’m glad this explanation has helped. And I feel the same way about having to explain these kinds of things to other people. It can be difficult.