Modal Verbs:

Obligation, necessity and permission.

Must and musn´t

Strong Obligation

Must and musn´t

Must *Affirmative form:Subject +must + verb (inf) + complement Examples:- You must go- You must visit us soon

Mustn´t *Negative form:subject + mustn´t + verb (inf) + complement Examples:- You mustn´t go to that meeting.-We musn´t be late

Interrogative form Must + subject + verb (inf) + complement? Examples:- Must you live now?- Must you travel to Barcelona tomorrow?

Must and mustn´t●Must is used to talk about strong

obligations in the present and future that are imposed by the speaker.

● The negative form of "must" expresses the idea that something is prohibitied.

Should, Shouldn't and Ought toWeak Obligation.

Should and Shouldn'tShould

*Affirmative form:Subject + should + verb (inf) + complement Examples:- (You look tired) You should take a nap.- I should study for tomorrow's test.

Shouldn't *Negative form:subject + shouldn't + verb (inf) + complement Examples:- You shouldn't run in the hallways- You shouldn't have talk to him like that.

Interrogative form Should + subject + verb (inf) + complement? Examples:- Should I talk to him? - Should I tell Mary about it?-Yes, you should - Yes, you should-No, you shouldn't - No you shouldn't

Should and Shouldn't

●Give suggestion on what is the right thing for somebody to do.

● Give advise or talk about what we

think is right or wrong. ● Make orders and instructions

more polite

Ought to*Affirmative form:Subject + ought to + verb (inf) + complement Example: -You ought to drive carefully-You ought to clean your room before you leave. *Hardly ever used in negative form:Subject + ought not/oughtn't to + verb (inf) + complement Example:-We ought not/oughtn't to have agreed without knowing what it would cost. *NOT USED in interrogative form.

Differences

Ought to

● You suggest someone what is one of the last options one has or something that one can't easily avoid, for example, any longer.

● It is more explicit, similiar to a

request. Example:-You ought to tell her how you feel.(You can't avoid telling her how you feel)

Should ● You suggest someone that

something is good to be done or something that after all is meaningful.

● It is not as explicit as ought to.

Example:- You should tell her how you feel.(It is better or the best to tell her how you feel)

Let's practice!

Create 3 sentences using "should" and "shouldn't"

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Create 3 sentences using "ought to" ---

Create 3 sentences using "must and mustn´t---