Must you?

To explain that something is necessary, we don't use "must" very much. Usually, we say "have to." And we say "have to," a lot. It is very common. In fact, I probably say it everyday.

Examples:
I have to go to the store for vegetables and milk.
I have to wake up early tomorrow.
I have to do my homework by Friday.
I had to write a report last week.

Although it is not very conversational, "must" is sometimes used for written rules. Sometimes you can see "must" in manuals or signs.

Examples:
Workers must wear a helmet.
Students must not use cell phones in class. 
You must be at work by 9:00am every morning.

However!! We do use must to mean that we believe something is true.

Examples:
You worked 10 hours today?! You must be tired.
That jacket is leather. It must be expensive.
It's hot outside. You must be thirsty.


Any questions?