Must - 28

                                                                                                                                                        

                         must  

Prior information                                               

What are auxiliary verbs?  Can,  could, may, might,  will, would, shall, should, must and ought are called auxiliary verbs. They are used with other verbs to add certain meaning like necessity obligation etc.

Base form of the verb – The base form of the verb go, went and gone is go

Short form of must not is mustn’t

Must doesn’t have Infinitive (to must) or participle (musting) or past (musted) form

Past and Past  participle form of verb – The past form of see is saw and participle form is seeing.

                              must usage

Must  is a modal auxiliary verb it is used to express obligation or necessity.

e.g. I must hurry (Otherwise I will miss the train)

       Joe must join the duty today. (Otherwise he will loose the job)

Must in questions

Must you pay the fee now?

Must they join tonight?

Must I Call him now?

Must in negatives     

She mustn’t  worry about the examination result.

You mustn’t touch the live wires

I mustn’t  forget to call Jim tonight.

Must be +  participle form

They must be joking = they have got to be joking

She must be hiding some vital information.

Must + have been

It must have been difficult for NATO forces to survive in Afghanistan.

It must have been terrible to see the burning plane.

I was told that you have been to Egypt. The visit must have been interesting.

Future obligation - equivalent of future must – will have to

Many European countries will have to face economic crisis (If they don’t  reform their financial system)

Shane will have to return by train, if she miss the last flight.

When you leave the college you will have to find a job.

Future obligation  - have got to

I have got to attend an interview next week .

I have got to see the dentist today. (I have severe tooth ache)

Past equivalent  of must  - had to

He had to walk three miles to school when he was ten years old.

We had to hire a cab last night. (We missed the last bus)

Must be + Past participle

Animals must be kept in special enclosures.

He must be woken up by 4 in the morning.  (otherwise he will miss the flight.)

Afghanistan must be the worst job for the US soldiers.

Must have + Past participle

There are no students in the class room. They must have left earlier.

I can’t find my diary here.  I must have kept it in the locker .

Must in orders

You must be here by noon tomorrow - Boss

Industries must improve their productivity (or face the penalty) - Government

Must and have got to

I must stop taking sugar (My strong desire)

I have got to stop taking sugar ( Doctor’s strong advice)

Must in negative conclusion.

She can’t be Joe’s sister.  (she is too young) - she mustn’t be Joe’s sister

They can’t be Americans. ( Their accent is British)