THAT vs. WHICH
Here are two more of those words that often cause us grief.
A restrictive clause contains information that limits the meaning of the thing being talked about. For example, in the sentence “Any book that you like must be good,” the relative clause “that you like” is restrictive becau
Luckily there’s an easy way to remember whether to use that or which. If the relative clause contains information that is not essential to the meaning of the sentence, and is also preceded by a comma, a dash, or parenthesis, it’s probably non restrictive, so use which. If not, odds are it’s restrictive, so use that.
However, the above distinction is a rule of formal American English, and is not as strictly observed in British English or in informal English of any type.
Clancy's comment: Mm ... American English?