That Which Has a Tail
Someone recently asked me the difference between that and which. I stumbled through a response, knowing I wasn’t doing an adequate job of it. Herewith, a (hopefully) better answer. By the way, if you speak the Queen’s English, the answer is short and sweet: there is no difference. But if you speak American English, read on.
That is a relative pronoun used for restrictive clauses, clauses that are necessary to the meaning of the sentence. If you didn’t have the clause, the sentence would mean something different. The clause restricts the meaning. For example:
I picked up the books that were on the table.
The books I picked up are limited to the ones on the table; I didn’t pick up the ones on the floor or on the shelf.
Which is a relative pronoun used for nonrestrictive clauses, clauses that add detail to the sentence but are not crucial to the sentence’s meaning. If the clause were taken out, the sentence would still make sense. The sentence’s meaning is not restricted. For example:
I picked up the books, which were on the table.
When I picked up the books, they were all on the table; there weren’t any on the floor or the shelf. That they were on the table is extra information.
Note the comma before which. If you’ve got a nonrestrictive clause, you need that comma and the which. They tell the reader some extra information is coming up. You can remember that the witch (which) has a tail (,):
Bryan Garner gives three guidelines for deciding if you need that or which (Garner’s Modern English Usage):
- “If you cannot omit the clause without changing the basic meaning, the clause is restrictive; use that without a comma.”
- “If you can omit the clause without changing the basic meaning, the clause is nonrestrictive; use a comma plus which.“
- “If you ever find yourself using a which that doesn’t follow a comma (or a preposition), it probably needs to be a that.“
Let’s see if you’ve got it. In the following sentences from Grammar Smart by the staff of The Princeton Review (30), choose the correct pronoun:
- The letter (that, which) came today was nicer than the one (that, which) came yesterday.
- Usually my mail, (that, which) is delivered at noon, is nothing but bills.
- A letter (that, which) is full of compliments is a joy to receive.
To see the answers, highlight the following text:
- The letter that came today was nicer than the one that came yesterday.
- Usually my mail, which is delivered at noon, is nothing but bills.
- A letter that is full of compliments is a joy to receive.
Loved this post. It’s the kind of grammatical rabbit hole that makes me feel both enlightened and slightly ashamed, like the time I discovered my ‘knowledge’ of semicolons was basically decorative. Now I’m tempted to go back through every email I’ve ever sent, replacing the rogue ‘which’es that should have been ‘that’s’ and leaving in the glorious ‘which’es which genuinely add extra detail. Somewhere out there, a past colleague is still scratching their head over a comma that should never have been invited to the party, and an editor which I tormented for years is finally breathing a sigh of relief. 😂
I got these right! Very clearly explained, thank you
Well explained, Erin. Almost no one knows this or takes the trouble to look it up.
Thank you, I often need reminding of this one!
I've changed "which" to "that" so many times when editing. Or added a comma before "which," but usually "that" is the correct choice in the sentences. Sometimes it seems like some people think "which" sounds fancier and try to use it more in formal writing, even if not correct.