This article is additional to the main page dedicated to Modal Verbs.
Some grammarians call the modal verb 'ought to' semi-modal. That happens because 'ought to' has some features of a main verb and some features of a modal.
Ought to meaning
We pronounce 'ought to' this way: [ˈɔt tu]
We use the modal verb 'ought to' when we want to show that something is good to be done according to moral concerns.
Also, we use it when we want to show the importance of a thing that you or someone else must do.
Another general meaning of 'ought to' is telling someone that he or she must do something in a polite way.
For example 👇
If you know someone's secret, you ought to keep it. (moral concern)
I think you ought to visit Grandma. She is very ill. (importance of a thing that you or someone else must do)
I'm so glad to have spent this wonderful evening with you, but I ought to go. (telling someone that he or she must do something in a polite way)
Ought to negative
When we want to use a negative form of the modal verb 'ought to' we take the particle 'not' and put it in the middle of the phrase:
ought to - ought not to
There is also a contracted negative form of this verb: oughtn't to
But you need to know that native speakers do not prefer to use the negative form 'ought not to'. They use 'shouldn't' instead.
Sarah, you ought not to speak with your mother this way. (not common)
Sarah, you should not speak with your mother this way. (better)
Ought to vs should
Nowadays it is common to use 'ought to' and 'should' interchangeably. But there is still a slight difference between them.
'Ought to' is a bit stronger than 'should'. We prefer to use it to speak about rules, duties and laws. And we use 'should' when we talk about our own, individual opinion, advice or truth.
But still, 'ought to' sounds more formal than 'should'. That's why we prefer 'should' in our every day speech.
You ought to follow the instructions, or you can get into trouble. It's dangerous to walk in this area.
You shouldn't go there. My friend got hurt in that area yesterday.
Ought to questions
Like all other modal verbs 'ought to' forms question without any auxiliary verb. We just take 'ought' and put it in front position.
Carol ought to go out.
Ought Carol to go out?
More examples with the modal verb 'ought to' 👇
Shreveport mayor: Coronavirus crisis ought to erase divisions between north and south Louisiana. The Advocate
He figured the tree, native to Pennsylvania, ought to be rising all over his hometown. Pittsburgh Post-Gazette
When an influential public figure dies, he ought to be laid to rest, and allowed to rest. The Punch
Coronavirus poses worker safety issues that ought to be more closely examined. Baltimore Sun
Sam McBride: The police's made-up Coronavirus law ought to unsettle anyone who understands democracy. Belfast Newsletter
State lawmakers ought to take such early interest in absentee voting as a call to action. Minneapolis Star Tribune