Ought to - Ought to have
We use "ought to" as modal verb to give advice and obligation. It is also used to express assumption, expectation and probability. It is also quite similar to Should.
Note: We don't use "to" with "ought" in negative sentence and we this use in this way "ought not go"
Formula: Subject + ought to + 1st form of the verb + object
Ought to Grammar
Obligation
Present
Examples:
You ought to obey your parents. (simple sentence)
They ought not leave without letting the boss know. (Negative sentence)
Past
Formula: Subject + ought to have + 3rdt form of the verb + object
Examples:
She ought to have led the team from the front. (Simple sentence)
You ought not have offended your mother. (Negative sentence)
Future
Examples:
Ibrahim ought to go with us to gym. (Simple sentence)
You ought not fight with your brother. (Negative sentence)
Advice
Present - You ought to complete your task on time.
Past - They ought to have apologized their father.
Future - We ought to respect elders.
Assumption - Expectation - Probability
Assumption - They ought to arrive here by the evening.
Expectation - He ought to have completed his task.
Probability - She ought to join us tonight.
Should
As it is mentioned above that "should" is used quite similar to "ought to".
Examples:
We should go hard against our opponent. (similar to ought to)
They ought to / should admit their mistake.
See also Should