Grammar | Modals | Must | Definition and Examples

 

MODALS

Hello students, today we are going to learn about one of Modal.

Modal: MUST

Definition:

Modals, also modals auxiliary verbs, modal verbs, modals auxiliaries, they are special verbs which behave irregularly in English. They are different from normal verbs as like as work, play, visit... They are given additional information about the function of the main verb that follows it. They have a very great variety of communicative functions.

MUST uses: 

Must has two POSSIBLE uses:

A- OBLIGATION / COMPULSION: 

She MUST = She HAS TO = She HAS GOT TO = She IS OBLIGED TO go now = She IS TO....

B- AFFIRMATIVE DEDUCTION: 

Mary said that she would call at 10:00 AM.                                                   

She always calls on time. The phone is ringing now, and it's                                                                   exactly 10:00 AM.

NOTE:

 IT MUST BE Mary (Do not say can be).

NOTE:

 For NEGATIVE DEDUCTION: Use CAN'T / COULDN'T.

_ Mary left to go fishing 10 minutes ago.

_ The phone is ringing now. Is CAN'T BE Mary / It COULDN'T.

NOTE:

BE Mary. (Do NOT say MUSTN'T BE).

1- Statements: 

I am obliged to finish this work today = I must / Have to / Have got to finish this work today.

2- Negatives: 

MUST has 2 negatives: 

a) MUSTN'T.

b) DON'T HAVE TO / HAVEN'T GOT TO / NEEDN'T:

Their meaning is VERY DIFFERENT.

- MUSTN'T indicates NEGATIVE OBLIGATION / PROHIBITION. It means it is FORBIDDEN / PROHIBITED. (You MUSTN'T /CAN'T / ARE NOT ALLOWED TO wear your shoes in a mosque) 

- NEEDN'T / DON'T HAVE TO / HAVEN'T GOT TO indicate ABSENCE OF OBLIGATION. They mean: It isn't NECESSARY / OBLIGATION. (We can choose whether or not we want to be is.)