Continuing that one article, which was about you know who.
Pronouns! Dontcha just love ’em?!
(Two pronouns, one sentence: Perfection.)
Anyway, as I said last week, I probably won’t be doing too many grammar articles, since there are far better resources out there, but this issue tends to be intertwined with “who vs. that” and so deserves a followup.
Fortunately, though “that” and “which” get mixed up a lot, there are fairly tight rules for each.
“That” is a restrictive clause, which means it’s essential for the meaning of the sentence.
Ants that travel together stay together.
If I tried to take out the clause containing “that,” I’d end up with:
Ants stay together.
Which is indeed a complete sentence, but it has lost meaning.
“Which,” on the other hand, is a nonrestrictive clause and is not essential to the sentence.
The airport, which was under construction, had numerous delays.
If I took out the “which” clause, I’d have:
The airport had numerous delays.
Which is both a complete sentence and still has meaning. The “under construction” bit explained why, creating additional information, but it doesn’t change the overall meaning of the sentence.
Notice that only “which” is surrounded by commas, another indication that it can technically be removed. “That,” with no commas, cannot.
This is all well and good for editing (certainly among the more simple corrections I have to make), but what about when writing? How do you decide when a clause is restrictive or not? Essential or not?
Again, it all depends on how necessary the information in the clause is.
The magazine that had coupons in it has gone missing.
The magazine, which had coupons in it, has gone missing.
If you have more than one magazine and you really wanted to find the one with coupons for 50% off any book at Barnes and Noble (ha), that first sentence’s clause is pretty important. It’s vital to what the sentence is trying to convey.
Conversely, if you have only one magazine and it happened to have coupons, you would be fine with the second sentence’s clause. Sure, those coupons may be important to you, but to the sentence, they’re not. “The magazine has gone missing” still relays all necessary information.
As in most writing, little choices like these provide more information than is explicit. Without you having to actually say so, the first sentence with “that” lets the reader know there are multiple magazines and you are looking for a specific one. The second sentence tells the reader there is only one magazine and you simply want to find it.
In short, “that” is for restrictive clauses (for necessary information) and “which” is for nonrestictive clauses (for additional information).