3 Must Flashcards
We use must to say that we f_____ sure something is t_____ .
We use must to say that we feel sure (subjective) something is true .
You worked ten hours today. You must be tired.
“Jim is a hard worker”. “Jim? You must be joking. He’s very lazy.”
I’m sure Sally give me her phone number. I must have it somewhere.
We use must not to say that we sure something is not true.
The phone rang eight times and Karen didn’t answer. She musn’t be at home.
They haven’t lived here very long. They mustn’t know many people.
Must also has another meaning. You must do something = it is n_____ to do it.
Must also has another meaning. You must do something = it is necessary to do it.
Workers must wear safety glasses at this machine.
In the USA, you must be 18 to vote.
Bicyclists mustn’t ride on the sidewalk.
Fort the past, we use had to (not must):
They were in a dangerous situation. They had to be careful.
We had to wear safety glasses when we visited the factory last week.
For the past, we use must (not) h_____ d_____ .
For the past, we use must (not) have done.
There’s nobody at home. They must have gone out.
“We used to live close to the freeway.” “Did you?” It must have been noisy.”
I’ve lost my gloves. I must have dropped it somewhere.
She walked past me without speaking. She mustn’t have seen me.
Tom walked into a wall. He mustn’t have been looking where he was going.
Action = must have + past participle
State = must have been + adj / past participle
Can we use have got to instead of have to (and vice versa)?
Can we use have got to instead of have to (and vice versa)?
Yes, we can:
I’ve got to work tomorrow = I have to work tomorrow.
He’s got to visit his aunt tonight = He has to visit his aunt tonight.
What’s the difference between can’t and mustn’t?
What’s the difference between can’t and mustn’t?
Can’t is “objective”.
Mustn’t is subjective.
Jo wants to eat. But he just had lunch. He can’t be hungry already. (= it’s impossible that he is hungry because he just had lunch)
I offered Bill something to eat, but he didn’t want anything. He mustn’t be hungry. (= I’m sure he is not hungry, ortherwise he would eat something)
Their car isn’t outside their house. They mustn’t / can’t be home.
Their car isn’t outside their house. They mustn’t be home. (subjective)
I just bought a box of cereal yesterday. It mustn’t / can’t be empty already.
I just bought a box of cereal yesterday. It can’t be empty already. (objective)
Must have or must not have. The jacket you bought is very good quality. It _____ (be) very expensive.
Must have / must not have. The jacket you bought is very good quality. It must have been very expensive.
Choose the right tense: There is a man walking behind us. He has been walking behind us for the last 20 minutes. He must _____ (follow) us.
Choose the right tense: There is a man walking behind us. He has been walking behind us for the last 20 minutes. He must be following us.
You just started filling out your tax forms 10 minutes ago. You mustn’t / can’t be finished with them already!
You just started filling out your tax forms 10 minutes ago. You can’t be finished with them already! (objective)
People in the front seat of a car _____ (wear) a seat belt.
People in the front seat of a car must wear a seat belt.
We had to / must wear safety glasses when we visited the factory.
We had to wear safety glasses when we visited the factory. (obligation in the past)
Choose de right tense: Ted isn’t at work today. He _____ (be) sick.
Ted isn’t at work today. He must be sick.
Must have or must not have. I can’t find my umbrella. I _____ (leave) it in the restaurant last night.
Must have or must not have. I can’t find my umbrella. I must have left it in the restaurant last night.
That restaurant must / must not be very good. It’s always empty.
That restaurant mustn’t be very good. It’s always empty.
