We use ”MUST”  to show ...

Expressing certainty that someting is false

Expressing near certainty that someting is true.

I smell bread baking.

There must be a bakery nearby.

She mustn´t working today.

George must is on the plane by now.

It's getting dark.

It must be quite late.

You haven’t eaten all day. You ________ hungry.

You look happy.

You ___________ the good news.

It's nearly eleven o'clock. They ________.

Look at their big house, it´s so luxurious! They_______________