Which is or that is

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 nonrestrictive, so use which. If not, odds are it's restrictive, so use that.

When to use that is VS Which is?

In a defining clause, use that. In non-defining clauses, use which. Remember, which is as disposable as a sandwich bag. If you can remove the clause without destroying the meaning of the sentence, the clause is nonessential and you can use which.

Can you replace which with that?

("That" can also be used to replace "which" without a comma. Using "that" (as opposed to "which" without a comma) is strongly preferred in the US.) My Persian carpet, which I bought in Qom, has been chewed by the dog.

When we use that is?

We use that to refer back to something that has already been spoken or written about: If he gets that job in London, he'll be able to visit us more often.

Is that and which interchangeable?

Although "which" and "that" are both pronouns, they are not interchangeable. "Which" is used for non-restrictive phrases, and "that" is used for restrictive phrases.