ought to

ought to — verb

1. used to express that a particular action is the right one to take based on moral

1.verbA2
Definition

used to express that a particular action is the right one to take based on moral rules, social expectations, or good judgment — for example, feeling that you ought to help a friend in trouble or that a government ought to protect vulnerable people.

Example

Eric knew he ought to apologise to his sister for his harsh comments.

ought to + base verb for moral obligation

Parents ought to spend more time listening to their children's worries and hopes.

Common collocations
  • ought to + base verb
  • ought to have + past participle
  • ought not to + base verb
Synonyms
  • should

    Nearly identical in meaning; 'should' is more common in everyday speech, while 'ought to' sounds slightly more formal or emphatic.

  • must

    Stronger — 'must' expresses urgent obligation or a rule, whereas 'ought to' is advice or moral expectation.

  • had better

    Carries a warning of negative consequences if the action is not taken ('You had better finish that report').

Antonyms
  • should not

    Negative counterpart expressing that an action is morally wrong or inadvisable.

Grammar Patterns

ought to + base verb

ought to have + past participle

ought not to + base verb

Usage Note

Softer than 'must' — 'ought to' gives advice or expresses moral duty rather than a forceful requirement. The negative form is 'ought not to' (formal) or, more commonly, 'should not' / 'shouldn't' in everyday speech. 'Ought to' does not change form for third-person singular (no 'oughts to'). In questions, the formal structure is 'Ought we to...?' but most speakers use 'Should we...?' instead.

Common Mistakes

You ought visit your grandmother more often.
You ought to visit your grandmother more often.
'Ought' must be followed by 'to' before the base verb in affirmative statements.
You don't ought to say that.
You ought not to say that.
The negative is formed with 'ought not to', not with 'do/does/did' support.
She oughts to call her mother.
She ought to call her mother.
'Ought' is invariable; it does not add -s for third-person singular.

2. expresses the idea that something will probably happen or is very likely true, b

2.verbB1
Definition

expresses the idea that something will probably happen or is very likely true, based on normal experience or on evidence you have — for example, saying that the train ought to arrive in ten minutes or that the keys ought to be in the drawer where you left them.

Example

The delivery ought to arrive before noon because the driver left the warehouse at nine.

ought to + base verb for expected event with reason clause

Eshe has been practising for months, so she ought to pass the driving test easily.

Common collocations
  • ought to + base verb
  • ought to have + past participle
  • ought to be + location or state
Synonyms
  • should

    Interchangeable in this prediction sense; 'should' is more frequent in casual conversation.

  • be likely to

    More explicit about probability; 'ought to' implies the speaker's reasonable expectation.

  • be supposed to

    Suggests expectation based on plan or schedule rather than general probability.

Antonyms
  • ought not to

    Negative form expressing that something is unlikely or not expected to happen.

Grammar Patterns

ought to + base verb

ought to have + past participle

Usage Note

Often used with time expressions ('by now', 'soon', 'by four o'clock') and with a reason clause explaining why the expectation is reasonable. The past form 'ought to have + past participle' expresses that something was expected to have happened already ('The train ought to have arrived by now'). Distinguished from sense 1 by being about prediction and probability rather than moral duty or advice.

Common Mistakes

He oughts to be home by now.
He ought to be home by now.
'Ought' is invariable regardless of person or number.
The package ought arrive today.
The package ought to arrive today.
The 'to' is always required before the base verb.

Synonym discussion

Sense: verb/1

Ought to, should, must, have to, and had better all express obligation or strong advice, but they differ considerably in strength and register. Ought to and should are the closest pair — both convey moral duty or sensible advice, with ought to sounding slightly more formal and weighty in British English. Must expresses a much stronger obligation, typically from the speaker's authority or conviction ('You must read this book — it is wonderful'). Have to points to an external rule or requirement ('Employees have to wear ID badges at all times'). Had better carries an implied warning: the consequence of not acting will be negative ('You had better tell the truth before someone else does'). In everyday American English, should dominates; ought to appears more often in writing, formal speech, and British conversation. For negative forms, ought not to and must not are rare in speech — most speakers use shouldn't and don't have to instead.

should ↗must ↗have tohad better ↗

Etymology

Old EnglishMiddle EnglishEnglish

Ought to comes from Old English 'ahte', the past tense of 'agan' meaning 'to own, possess, or owe'. The idea of owning a debt gradually shifted to expressing a moral duty — something you owe to others or to yourself. The 'to' infinitive marker attached over time, forming the fixed modal phrase 'ought to' that we use today.