When do you use which and when do use that?

Question

Which is used as an interrogative pronoun.. That is a a demonstrative pronoun or a noun determinator.

Answer 1

You're absolutely right about the primary uses of "which" and "that"

1. Which: Primarily used to introduce questions (interrogative pronoun) or to refer to options within a defined set.
2. Example (question): Which flavor of ice cream do you prefer?
3. Example (options): I have several books, which would you like to borrow?
4. That: Primarily used to point to specific things (demonstrative pronoun) or to introduce clauses that are essential to the meaning of a sentence.
5. Example (pointing): That is my favorite painting.
6. Example (essential clause): The book that I borrowed from the library is due tomorrow.

The trickier part is when you're using "which" and "that" to introduce clauses in sentences. Here's the general rule:

1. That: Use "that" to introduce a restrictive clause. This is a clause that's essential to the meaning of the sentence and cannot be removed without changing the meaning.
2. Example: The car that I bought last year is already having problems. (The clause "that I bought last year" is essential because it tells us which car is being discussed.)
3. Which: Use "which" to introduce a non-restrictive clause. This is a clause that adds extra information but isn't essential to the meaning of the sentence. These clauses are usually set off by commas.
4. Example: My new car, which is red, is already having problems. (The clause "which is red" is not essential to the sentence's meaning – we still know which car is being discussed without it.)

Remember: There can be some flexibility in less formal writing, but following this general rule will help you use "which" and "that" correctly in most cases.

Answer 2

I'm a little confused by the information that you give after your question. Usually, when we teach about when to use "which" and "that," it is in the context of them being relative pronouns. Relative pronouns start adjective dependent clauses. For example:

I talked to the person that/who was sitting behind the counter. (In this sentence it is acceptable to use "that" or "who" because the dependent clause that begins with "who/that" describes "person." Use "who" or "that" for people. Some might say that in the strictest sense, we should only use "who" to start a dependent clause that describes people, but in reality, "that" is also used.

He gave me the hammer which/that was exactly the tool for the job. (In this sentence, it is acceptable to use "that or "which" because the dependent clause that begins with "that/which" describes at thing, "tool." Use "which" and "that" for things.

"Which" is also used as an interrogative pronoun as you mentioned. For example: Which of the cleaners do you want me to use?

"That" can also be a demonstrative adjective or noun determiner as you mentioned. For example: Give me that pencil, please.

"That" can also be a demonstrative pronoun. For example: That is my pencil.

I hope this helps to answer your question.

Answer 3

The grammar rule states the following: Use which for things not people. That is used for both humans and actors.