Obligation and necessity

Obligation and necessity

Must/ mustn't

• when the speaker feels that an action is necessary: I must call my brother today. (he is ecpecting my phone call)

• by someone in authority, e.g parent, boss,teacher : You must hand in your assignment by Tuesday.

• in writte rules, instructions :All accidents must be reported to the police

Multiple Choice

You .................touch that! You will hurt yourself.

• mustn't

• don't have to

Multiple Choice

You............to your father like that!

• need to

• mustn't

Have to (have got to)/ had to/ did not have to

• when an action is necessary, because someone else requires it or because it is a rule or law.: You have to wear school uniforms in this school

• for habits : I have to catch the bus to work every day

• Use don't have to when there is no obligation to do something.: You do not have to wait

Multiple Choice

Peter .......... to pick me up from the airport. I'll take a taxi.

• doesn't have

• mustn't

• doesn't need

• must

Need to / needn't/ don't need to /didn't need to

• we use needn't and don't need to talk about lack of necessity in the present or future.: You needn't come or you don't need to come to the party. (if you do not want to)

• Don't have to and don't need to are similiar and you can choose which one to use

Fill in the Blank

You ......................in a hostel . You can stay with us. (stay)

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They..............late tonight. They can finish the job tomorrow.

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I.......... ring my parents. I am really worried about them.

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You ..........park your car here, you will get a fine

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You ............hurry. There's plenty of time

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You.............forget to switch off all electric appliances before you leave the building

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Why ................leave so suddenly? Was anything wrong?

Multiple Select

We..............get up early, because we do not have morning classes

• mustn't

• don't have to

• don't need to

• need to