Now you'll have to produce another sentence using the same intonation. Imagine you're talking with your brother. You have asked him many times to return a book to you, but he has not done so. Ask him whether he can return it to you. After saying this, listen to how it is pronounced.
Now imagine you are walking down the street and someone grabs you from by the shirt twice and when you turn around you see no one. Finally, when this happens a third time you notice behind you someone you know that always likes to tease you. Annoyed, you demand, "What do you want?" After saying this, listen to how it is pronounced..
Now imagine you are talking to your friends on the street. A rude neighbor comes along, immediately barges into the conversation and interrupts what you're saying. Angrily, you say, "Why don't you shut up?". After saying this, listen to how it is pronounced.