ملخص الدرس / الثانية متوسط/اللغة الإنجليزية/File 3/Expressing Obligation - Prohibition

Obligation

We use mustto speak about the things we are obliged to do and the necessary things to us.

Rule :

Subject+must/mustn’t+stem

 

Eg1: You must see a dentist.

Eg2: we must study hard to succeed

Prohibition

We use must not /mustn’tto speak about the things we are prohibited from doing.

Rule :

Subject+mustn’t+stem

 

Eg1: You mustn’t use your phone all the time.

Eg2: He mustn’t eat unhealthy food.

Asking questions

Rule :

Must+subject+stem?

Eg1: Must you go now?

Eg2: Must we be in class at 8am?

Using "must":

To talk about something that is necessary for me (or another person) to do (but it's just a personal opinion or a rule that I have made myself), I use: "must + V (stem/base)".

eg: You must go to the dentist.

I must remember to buy a red pen. In modern English, I can generally use "must" or "have/has to" in:

Questions: eg: Must I take this cough syrup, mum? =Do I have to take this cough

syrup, mum?)

Affirmative (positive) sentences:

eg: Liz must take her cough syrup. (=Liz has to take her cough syrup.)

 

Using "have t

Talking about things that are necessary for me to do (obligation) 

To talk about something that is necessary for me (or another person) to do (because it's a law, a duty or a fact),

I use: "have/has to + V (stem/base)".

eg: I have to get a passport if I want to travel to other countries. (It's a law.)

She has to take care of her sick mother. (It's a duty.)

I have to go to the dentist.

I have an appointment at 3 pm. (It's a fact.)

In informal British English, I can use "have/has got to" instead of "have/has to".

eg: I have got to get a passport if I want to travel to other countries.

 

 

Interrogative and Affirmative (Positive) Forms:

"Have to":

Interrogative form: "Do/Does + S + have to + V ...?"

eg: Does he have to come back for a check, doctor?

Affirmative form: "have/has to + V"

eg: She has to take her medication every day.

"Must":

Interrogative form: "Must + S + V ...?"

eg: Must she stay in bed, doctor?

Affirmative form: "must + V"

eg: You must take a rest.

Negative Form:

 "don't/doesn't have to + V

When I say that I don't have to do something", it means that it's not necessary for me to do it, but I can do it) if I want to.

eg 1: I don't have to get up early on Friday morning (but I can get up early if I want to).

eg 2: I don't have to get a passport if I want to travel to other countries. (I can't use "don't have to" in this example because it is necessary for all Algerians to have a passport if they want to travel to any country in the world! I can't travel without a passport!)

"mustn't + V

When I say that “I (or another person) mustn't do something", it means:

Don't do it. It is forbidden. It is a prohibition.

eg: I mustn't eat too much. I mustn't smoke.

You mustn't wear eyeglasses without consulting an ophthalmologist.

Pronunciation

Example

pronunciation

She must brush her teeth.

/mʌst/

We mustn’t go out without the permission of our parents.

/mʌsnt/ or /məs(t)/ (both are correct)

Must he do all the exercises in the book?

/məs(t)/

Yes, he must.

/mʌst/

No, he mustn’t.

/mʌsnt/

the rule:

/m∂s(t)/is the weak form of "must". It is generally used in questions or in the middle of statements.

Final"t" is usually silent (not pronounced).

In short answer questions "have to" is more common than "must",

Example: Does Amy have to go on a diet, doctor?

/m∧st/ is the strong form of "must". It is used in short answers.

"mustn't" is the contracted or short form of "must not". It is pronounced m∧snt.

The first "t" is silent (not pronounced).