Modal verbs must, should, ought to - English in use (2024)

Modalverbs part 2 - obligation :
must,have to, should and oughtto , need to

Firmobligation,etc. - mustand have to (and got to)

The verb mustonly existsin the simple present and present perfect forms.
While the presentform can express

or strong

,the present perfectforms onlyexpress a strongly felt opinion or

.

If other tenses are required, the speaker or writer must use forms ofthe synonymous modal verb "haveto" . This modal auxiliary has all normaltenses, including progressive or continuous forms; these are notcommon, but need to be used in some cases.

* The form"had not to"is sometimes used, but it is generallyconsidered to be archaic.

Examplesofmust and have tobeing used to express :
a. Firm

or

b.

or strong

.
c. Must haveonly :

Takecare !
Take care to distinguish correctly between "had to"and"must have"

They hadto go toLondon
= Theywere obliged to go to London
Theymust have gone to Chicago
= Inmy opinion, they have certainly gone to Chicago.

Gotto :

In informal styles, most commonly in the

,haveto is often accompanied by the word got,particularly in spoken English.
For example an alternative to I haveto is I've gotto.
More examples:

He'sbroken my computer, so he's got toget me a new one.
We're late, we've got tohurry.
You've got to work harderif you want to get top marks.

Before got, the auxiliary have is almost always contracted(i.e. They've got, not they have got).
For more on got, see Getand got

► Other uses of the verb have:seetheverb to have.

Must and have to in negative contexts

It is vital to remember that must not anddon't have to are NOT synonyms – indeedthey mean two completely differentthings.

Must not implies negative obligation (i.e. being forbidden to do something)
Don't have to (like haven't got to) implies the absence of obligation (i.e. having no obligation to dosomething)
Compare:

They mustnot go toLondon
= Theymust stay away from London, they cannot go there.
They do not have to go toChicago.
= Theyare not obliged to go to Chicago,but they can go there if they wish.

Recommendationor moral obligation - shouldand oughtto, need to

a) should, ought to

The verb shouldonly existsin the simple present, and present perfect forms
Forms ofshould

The verbought toonly existsin simple present and present perfect forms
Forms of ought to

Shouldand ought toare more or less synonymous

Examples:
a1)Youshould stop smoking ( = Youought to stop smoking.)
a2) It's raining hard, the childrenought to come indoors.
a3) I didn't know you were married ! You oughtto have toldme !
a4) If you'd wanted to succeed, you shouldhave worked harderat school.
a5) This pullover's got holes in it, I shouldget a new one.
a6) This pullover's got holes in it, I oughtto get a new one.
a7) That's awful ! You really oughtn'tto have done that, youknow !

b)Need to :

Used affirmatively, need toimplies strong recommendation; but used negatively it expresses anabsence of obligation. There are two negative forms of need,either don’tneedto orneedn’t.

Take care! Needn’tis neverfollowed by to.Needis also used as a main verb followed directly by anobject, asin Ineed you.

Examples:
b1) I’ve been working non-stop for sixhours, I need to take arest.
b2) I think you’ve got covid….. you needto get tested at once.
b3) Thank goodness, I haven’t got covid, so I don’tneed to stay at home
b4) Thank goodness, I haven’t got covid, so I needn’tstay at home.