Relative Pronouns

used in questions to ask about the name or identity of one person or several people

Who are those people sitting at the back?

used to ask or talk about one or more members of a group of things or people, when we are not sure about it or about them

Which of these options is the best solution to the problem?

used to identify a specific person or thing observed or pointed out by the speaker

That is my brother standing by the car.

used to ask questions about objects or indirect objects in sentences

Whom did you invite to the party?

used to show that the thing mentioned belongs to a particular person or thing

She's an author whose novels have topped the bestseller list.