UNIT I -- MUST-MUSN’T

MUST-MUSN’T

We use must to indicate duty or obligation to do something; we could translate it as having to or duty. Be careful, because in its negative form, mustn’t indicate prohibition. To talk about something you don't have to do, but you could, we use not + have to: you don't have to eat that if you don't want to t smoke in here

 

VERB MUST

The verb Must expresses obligation from a subjective level; that is, from the personal point of view of the speaker. For example:

-You must stop using your cell phones in class.

-You must pay attention to all my explanations.

-The two sentences express an obligation raised from the subjective point of view.

 

VERB MUSN’T

Must not or musn't, is used in formal situations and mustn't in informal situations. Must not and Mustn't express that it is not allowed to do something, either from a subjective perspective. It is also used to express prohibitions from an objective perspective such as: a natural, social, legal or administrative law.

For example:

-Employees must not wear casual clothes at the office.

-You mustn’t talk to strangers.

-Employees must not take naps after lunch.

-You mustn’t play video games when I am not at home.

 

After this modal verb we must NOT use TO. We have to use the base form of the verbs as follows:

-I must play

-I must play

-They must play

 

In English we use the modal verb must for the present and for the future but not for the past:

-Present: I must call my boss.

-Future: You must come to the office tomorrow