Did you know: 'must' and 'have to'?

Must and have to are both used to indicate obligation and are often quite similar. They are both followed by the infinitive.

I have to sleep now.
I must sleep now.

Here is how we tell the difference between the two:
1. we use must for more personal opinions about what it is necessary to do. (internal drive)
2. we use have to for what somebody in authority has said it is necessary to do. (external drive)

I must sleep now to have enough rest for the exam. (In my opinion)
I have to sleep now, otherwise my mom will be mad at me. (My mom wants me to sleep early)
Do you have to wear a uniform for school? (asking about school rules)
Drivers must fasten their seat-belts. (that is the rule)

But, they are totally different in the negative:
1. You must not eat in class. (You must not - you have no choice)
2. You don't have to wait for me. (There is not obligation to wait for me, but you have a choice)

Is it must, have to, mustn't or don't have to?
1. I _____ save money for my holiday.
2. When the traffic light turns red, you _____ stop.
3. If you are not hungry, you _____ eat again. You can go play with with friends.
4. You _____ put medicines in the fridge. Your kids might eat them as candies.
5. What _____ you do to make things better?
6. I have brought an umbrella. So, you _____ bring one.
7. When you are in a library, you _____ talk and chat with a friend.
8. You _____ get 3.5 in the next exam if you want to pass Biology.
9. Since you have got an English book from your sister, you _____ buy another one.
10. You _____ show a ticket when you are getting into a cinema.

We often use must for more personal opinions about what it is necessary to do, and have to for what somebody in authority has said it is necessary to do. - See more at: http://learnenglishteens.britishcouncil.org/grammar-vocabulary/grammar-videos/have-must-and-should-obligation-and-advice#sthash.S97OlBgr.dpuf

We often use must for more personal opinions about what it is necessary to do, and have to for what somebody in authority has said it is necessary to do. - See more at: http://learnenglishteens.britishcouncil.org/grammar-vocabulary/grammar-videos/have-must-and-should-obligation-and-advice#sthash.S97OlBgr.dpuf

We often use must for more personal opinions about what it is necessary to do, and have to for what somebody in authority has said it is necessary to do. - See more at: http://learnenglishteens.britishcouncil.org/grammar-vocabulary/grammar-videos/have-must-and-should-obligation-and-advice#sthash.S97OlBgr.dpuf

We often use must for more personal opinions about what it is necessary to do, and have to for what somebody in authority has said it is necessary to do. - See more at: http://learnenglishteens.britishcouncil.org/grammar-vocabulary/grammar-videos/have-must-and-should-obligation-and-advice#sthash.S97OlBgr.dpuf

We often use must for more personal opinions about what it is necessary to do, and have to for what somebody in authority has said it is necessary to do. - See more at: http://learnenglishteens.britishcouncil.org/grammar-vocabulary/grammar-videos/have-must-and-should-obligation-and-advice#sthash.S97OlBgr.dpuf

We often use must for more personal opinions about what it is necessary to do, and have to for what somebody in authority has said it is necessary to do. - See more at: http://learnenglishteens.britishcouncil.org/grammar-vocabulary/grammar-videos/have-must-and-should-obligation-and-advice#sthash.S97OlBgr.dpuf

We often use must for more personal opinions about what it is necessary to do, and have to for what somebody in authority has said it is necessary to do. - See more at: http://learnenglishteens.britishcouncil.org/grammar-vocabulary/grammar-videos/have-must-and-should-obligation-and-advice#sthash.S97OlBgr.dpuf