The choice of a relative pronoun used to introduce a relative clause depends on a number of things. The first consideration is whether the clause is restrictive (needed for the sentence's meaning) or non-restrictive (additional information that is not needed for the sentence's meaning).Originally Posted by Anonymous
In this case, it could be either. If your point is that that cat you have is cute, the clause is restrictive. If your point is that you own a cat, and then you just happen to mention that the cat is cute, the clause is nonrestrictive. Restrictive clauses are not set off with commas; non-restrictive clauses are set off with commas.
The uses of "which" and "that" are a bit different in American English and British English. Both varieties of English use only "which" in non-restrictive clauses. In AE, we tend to use only "that" for restrictive clauses. In BE, both "which" and "that" are used in restrictive clauses.
In both varieties, "who" can be used for either restrictive or non-restrictive clauses. Either "that" or "who" can be used for a person, though most people prefer "who". Many, but not all, would be comfortable using "who" for an animal.
John: Do you have any pets?
AE Mary: I have a cat, who/which is very cute. (non-restrictive)
BE Mary: I have a cat, who/which is very cute. (non-restrictive)
John: I have never seen a cute cat.
AE Mary: I have a cat who/that is very cute. (restrictive)
BE Mary: I have a cat who/that/which is very cute. (restrictive)
Does that help? :wink: