must 必須,一定
命令或強制
such as when you are in the MTR, so you must not drink or eat.
cannot 不能
such as when you are in the classroom, you cannot drink or eat without teacher's
permission, but it doesn't mean that you cannot drink or eat.
You cannot eat and drink. 你不能夠進食或飲水。例如施完手術後便不可立即飲食,因為身體未能回愎運作。
You must not eat and drink. 你千萬不要進食或者飲水/其他飲料。 這個是急情的叮囑。
You cannot run. 你不可以跑步。
You must not run.你千祈不要跑啊!