That and Which

English Student   Thu May 31, 2007 4:17 am GMT
When do I use that and when do I use which? Are there rules? Can I use both in the same sentences?
furrykef   Thu May 31, 2007 5:12 am GMT
Perhaps the easiest explanation is that, at least in American English, you should use "which" when you need a comma before it, and "that" when you don't. But it's only a rule of thumb, and it's often ignored, using "which" in either case. (However, "that" can't follow a comma unless it's not being used as a relative pronoun.)

* I found a rare coin that/which was lying on the ground. ("That" is preferable, but "which" is possible)
* The coin was valuable, which was a good thing. ("That" cannot be used)

Unfortunately, it's difficult to clarify the matter further than that... sometimes "which" sounds better than "that" even when the rule says "that" should be used, and we can't really explain why. It's not really a major issue, though.

- Kef
Jim   Thu May 31, 2007 8:42 am GMT
It's easy to explain why. The "rule" was pulled out of thin air by Fowler but has never been completely followed by all.

The distinction here it restrictive vs. non restrictive clauses. If it's non restrictive, use "who" or "which". If its restrictive, use whatever you like but if you're a stickler for made-up rules, use "that".

"Restrictive" means that the info added is vital to the sentence. "Non-restrictive" means it's extra info. As says Kef, you break the non-restrictive clauses off with commas (or the like).
furrykef   Thu May 31, 2007 11:21 am GMT
<< It's easy to explain why. The "rule" was pulled out of thin air by Fowler but has never been completely followed by all. >>

That doesn't explain *why* "which" sometimes sounds better, it just allows the possibility. ;) In other words, it points out that the rule is inadequate, but without providing a better rule.

- Kef
Guest   Thu May 31, 2007 4:11 pm GMT
''* The coin was valuable, which was a good thing. ("That" cannot be used) ''


Of course it can: The coin was valuable. That was a good thing ;)
furrykef   Thu May 31, 2007 6:51 pm GMT
Yes, but you cheated by using "that" as a demonstrative rather than a relative pronoun and putting it in a different sentence. ;)
Guest   Sat Jun 02, 2007 12:10 pm GMT
Thanks for the information, which was very good at that.