1. Who: We use in a relative Clause when we are talking about people (not things). We use who instead of He/She/They Examples: The woman who is wearing a pink dress is my mother. I prefer the people who is shy. The man who sold the car is my neighbor.
2. That: When we are talking about things, we use that or which (not who) in relative clause. Examples: I work with people that are responsible. Elias is dating a woman that works in my company. My sister bought a car that is expensive.
3. Which: That is more usual than which. But sometimes you must use which (not that). Examples: My brother bought a smarphone which is expensive. My son does not play video games which contain violent scenes. Every night Iread articles which teach me something new.
