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 Blanks

You

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

Fill in the Blanks

They

late tonight. They can finish the job tomorrow.

Fill in the Blanks

I

ring my parents. I am really worried about them.

Fill in the Blanks

You

park your car here, you will get a fine

Fill in the Blanks

You

hurry. There's plenty of time

Fill in the Blanks

You

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

Fill in the Blanks

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