MODALS(Modals that express necessity or

obligation)

Read the following statements:

1. I need to pay the bills.2. I must accomplish the reports.3. The king ought to know more

about his enemies.

Modal Verbs of Obligation

Remember the following points.Modals are auxiliary verbs performing specific functions. Some examples are:•Must – express obligation•Need to – indicates necessity•Should and ought to – express sense of obligation to do, or to become something•Shouldn’t and should not have, or ought not – indicate prohibition, or disapproval of something that was done in the past.

Modal Verbs of ObligationTo express obligation (something you have to do), we can use the following:

a.have to + infinitiveb.must + infinitivec. should + infinitive

Modal Verbs of Obligation

Present Positive Negativehave to / don't have

to

strong obligation (possibly from

outside)Children have to

go to school.(sometimes

'have got to')

no obligationI don't have to

work on Sundays.

You don't have to eat anything you don't like.

Modal Verbs of Obligation

Present Positive Negativemust /

mustn'tstrong

obligation (possibly

based on the speaker's opinion)

I must study today.

negative obligation

You mustn't smoke here.

Modal Verbs of Obligation

Present Positive Negativeshould /

shouldn'tmild obligation or adviceYou should save some money.

mild negative obligation or adviceYou shouldn't smoke so much.

Modal Verbs of Obligation

Be careful about the difference between mustn't and don't have to! - Mustn't means it's not allowed, or it's a bad idea: You mustn't eat so much chocolate, you'll be sick - Don't have to means you don't need to do something, but it's fine if you want to do it: I don't have to get up early at the weekend(of course, if I want to get up early, that's fine, but I can stay in bed if I want).

Modal Verbs of Obligation

Past Positive Negativehad to / didn't

have to

should have + pp / shouldn't have

+ pp

obligation in the past•I had to wear a school uniform when I was a child.

a past action which didn't happen: the advice / regret is too late•You should have gone to bed earlier, now you have missed the train.

no obligation in the past•We didn't have to go to school on Saturdays.a past action which didn't happen: the advice / regret is too late•You shouldn't have taken that job, it was a bad idea.

Modal Verbs of Obligation

•Write at least five desirable traits or habits you need to develop, and five habits you ought to weed out.•Write a short paragraph persuading others on the importance of developing these desirable attitudes and weeding out the undesirable habits to win over challenges. Use this title: “Habits and Traits to Develop or to Weed Out in Order to Win over Challenges.” Clarify your stand and use words that appeal to reason or emotion. Remember to use the appropriate modals.