But what about if you are talking about someone and you don't know if that person is a man or a woman? Or if you don't want to specify?
Then you use they. They usually refers to two or more people, but in this case, they is one person, and it can be a male or a female.
Examples: I am going to take my driving test. Will the examiner be a man or a woman? I don't know...So I say, "I hope they are nice."
My son says, "I have a new English teacher." I don't know if it's a male or female teacher, so I say, "Oh, what's their name?"
How much can you tell about someone from their choice of car?