I'm sure that Brenda isn't over thirty. Brenda...
Brenda can't be over thirty.
It would be a great idea if Harry took a holiday. Harry...
Harry should take a holiday.
I advise you to see a dentist.You...
You should see a dentist
It looks like he is looking for something. He...
He may/might/can/could be looking for something.
Why aren't you at home revising for your exam? You...
You should be revising for your exam at home now.
Maybe Tom is looking for a new place to live. Tom...
Tom could be looking for a new place to live.
I'm sure that Helen feels really lonely. Helen...
Helen must feel really lonely.
Students are not allowed to leave the classroom. Students...
Students mustn't/can't leave the classroom.
I bet I look silly in this coat. I...
I must look silly in this coat
You're not allowed to park here. You...
You can't/mustn't park here.
I'm sure she thinks I'm stupid. She...
She must think I'm stupid
It is a bad idea to go into that abandoned castle at night. We...
We shouldn't go into that abandoned castle at night.
I know that isn't Janet-She's in America. She...
She can't be Janet
It’s possible the weather will be sunny tomorrow. The weather...
The weather may/might/could be sunny tomorrow.
I'm sure she's at home. She..
She must be at home
You aren’t allowed to talk during the exam. You...
mustn't / can't talk during the exam