Modal verbs show likelihood, ability, necessity, permission and obligation, but that's not all!
MUST IS A MODAL AUXILIARY VERB AND THERE IS NO -s IN THE THIRD PERSON SINGULAR:
- He must finish his work on time. (not: He musts finish...)
WE DON'T USE TO AFTER MUST:
- I must go now. (not: I must to go)
USED FOR SAYING THAT IT IS NECESSARY OR IMPORTANT TO DO SOMETHING:
- Plants must be watered regularly.
- You must understand that I can't do all this alone.
USED FOR ORDERING SOMEONE TO DO OR NOT TO DO SOMETHING:
- You must stay in bed until you get better.
- You must stop talking.
- You must go home immediately.
USED FOR SAYING THAT SOMETHING IS PROBABLY TRUE:
- You've been working for hours on end. You must be exhausted.
- There must be some mistake. I didn't do anything wrong.
- There must be something wrong with the engine.
USED FOR SAYING THAT IT'S YOUR DUTY TO DO SOMETHING:
- We must protect our children.
- We must defend the freedom of our people.
USED FOR SUGGESTING SOMEONE THAT THEY SHOULD DO SOMETHING BECAUSE THEY WOULD ENJOY IT (STRONG SUGGESTION):
- You must see the latest James Bond film! It's fantastic!
- You must try this cake, it's delicious!
- You must come and visit us again some time.
USED WHEN WE EMPHASIZE THAT WE NEED TO DO SOMETHING:
- I must introduce you to my brother.
MUST AND HAVE TO
(They both show obligation and necessity, but with a subtle difference)
WE USE HAVE TO TO SHOW THAT THERE IS AN 'EXTERNAL AUTHORITY',
compare:
- I have to wear a uniform at school. (It's a rule - coming from the 'outside')
- I'm meeting my boyfriend's parents and I must look my best. (I want to look my best - the obligation is coming from the speaker, 'inside')
- I have to arrive at 9 sharp. My boss is very strict.
- It's getting dark. I must go home now.
WE USE HAVE TO FOR DIFFERENT TENSES BECAUSE THERE IS NO MUSTING, MUSTED, WILL MUST:
- I had to study so I couldn't go out. (past)
- We'll have to get a new passport soon. (future)
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| BY SA Nina Paley |
WE USE DON'T HAVE TO TO SHOW THAT SOMETHING IS NOT NECESSARY TO BE DONE:
- When you buy something on credit it means you don't have to pay for it at once.
- I don't have to get up tomorrow, because it's Saturday.
*NOTE: MUSTN'T DOESN'T MEAN THAT IT ISN'T NECESSARY TO DO SOMETHING. IT SHOWS STRONG PROHIBITION. (WE ARE NOT ALLOWED TO DO SOMETHING)
- You mustn't talk to strangers.
- You mustn't feed the animals in the zoo.
WE USE HAVE TO TO MAKE QUESTIONS:
- Do you have to travel a lot on business?
- When do you have to be back?
