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belyaeva-petrischeva

1) Modals to express obligations

  1. Must expresses a strong obligation.

All visitors must report to Reception.

You mustn’t steal things! Its naughty!

  1. Have to express a general obligations based on a law or a rule.

Nurses have to wear a uniform.

Malcolm has to drive a thousand miles a week in his job.

  1. Sometimes must and have to are similar.

I must go now. Cheerio! I have to go now. Cheerio!

Sometimes there is a difference. Must is personal. We use must when we express our personal feelings, and say what we think is important or necessary.

You must work harder. (I am telling you what to do.)

I must wash my hair. It`s dirty. (I am telling myself that it`s necessary.)

Have to is impersonal. It expresses a general obligation based on what another person tells us to.

We have to wear a stupid uniform. (It`s a school rule.)

I have to take this medicine three times a day. (The doctor said.)

  1. Have to is used to form the question, and the past and future.

Do you have to work full-time?

I had to get up very early when I was at school.

You`ll have to work hard if you want to go to university.

  1. Should expresses what is right, or a good idea. It expresses advice, or a mild obligation.

You should get more exercise. Why don’t you play tennis?

You shouldn’t eat so many sweets. They are bad for your teeth.

Negatives

Mustn`t and don’t have to express very different ideas.

You mustn’t take drugs. (This is a strong obligation not to do something.)

Teenagers don’t have to go out to work. (There is no obligation, but they can if they want.)