58 - Expressing prohibition

A: My table manners are terrible! I eat like a
hungry animal. Please teach me the polite way to eat.
B: Alright. First, never chew with your mouth
open. Also, don’t talk with food in your mouth. A: I got it.  
B: Not only that, don’t make loud noises. Try to eat as quietly as possible.
A: And when should I start eating?
B: You must wait until everyone is seated at the table before you begin eating.