Выразите запрещение при помощи отрицательной формы глагола “must” (mustn’t) You mustn’t do it Вы не должны (вам нельзя) этого делать to come late to your classes; to miss your English classes; to make noise here; to talk at the lectures; to read in the darkness; to call him so late; to smoke in the children’s room;

You mustnt come late to your classes/ You mustnt miss your English classes/ You mustnt  make noise here/ You mustnt talk at the lectures/ You mustnt read  in the darkness/ You mustnt call him so late/ You mustnt smoke in the childrens room.