Should and ought to are close cousins. Both give advice: "You should rest" and "You ought to rest" tell you the same thing. Both can also state an expectation: "The parcel should arrive today" means it is likely.
The grammar around them differs. Should takes the base verb with no to. Ought always takes to. Should makes questions and negatives easily, while ought to sounds formal and old-fashioned in those forms.
This page compares the two, shows should have and ought to have for past criticism, and finishes with a 20-question drill. Each answer explains which verb fits and why.
The rule
Nearly the same meaning
- Should and ought to both give advice: "You should rest." / "You ought to rest."
- Both can state an expectation: "The parcel should arrive today."
- Ought to sounds a little more formal and a little stronger.
- In everyday speech, should is far more common.
Form and the to rule
- Should takes the base verb with no to: "You should go."
- Ought always takes to: "You ought to go."
- Neither verb changes with the subject: he should, she ought to.
- Never mix the patterns: "You should to go" and "You ought go" are both wrong.
Questions and negatives
- Questions use should: "Should I call her?"
- Negatives use should not or shouldn't: "You shouldn't worry."
- Ought to in questions is very formal: "Ought I to call?"
- Use should for the negative: "You shouldn't eat so late."
Advice, expectation and criticism
- Advice about the present or future: "You should drink more water."
- Expectation based on a plan: "They should be here by six."
- Criticism of a past action uses should have: "You should have told me."
- Ought to have works the same way but is rarer: "You ought to have told me."
Should, must and had better
- Must is stronger than should: "You must wear a seatbelt."
- Should is a recommendation: "You should wear a coat."
- Had better warns of a bad result: "You had better hurry, or we will miss it."
- Choose must for rules, should for advice and had better for a warning.
Examples
- You should rest after the journey.A recommendation about the present.
- You ought to rest after the journey.The same advice in a slightly more formal form.
- She should call her mother tonight.Advice about a future action.
- The train should arrive at six.Expectation based on the timetable.
- Should I open the window?Questions take should.
- You shouldn't eat so late.Negatives take should not or shouldn't.
- You should have booked earlier.Should have criticises a past action.
- You ought to have booked earlier.Ought to have does the same job more formally.
- We had better leave now, or we will miss the train.Had better warns of a bad result.
- Passengers must wear a seatbelt.Must states a rule, which is stronger than advice.
Common mistakes
- Wrong: You should to rest. Right: You should rest.
- Should takes the base verb and never to.
- Wrong: You ought rest. Right: You ought to rest.
- Ought always takes to before the base verb.
- Wrong: Should I to call her? Right: Should I call her?
- In questions, should keeps the base verb with no to.
- Wrong: You don't should worry. Right: You shouldn't worry.
- The negative of should is shouldn't, with no do-auxiliary.
- Wrong: You should have tell me. Right: You should have told me.
- Should have takes the past participle told.
Practice drill
Answer all 20 questions. Each answer is marked at once, and the rule is explained under the question.
You ___ rest after the journey.
Show answer and explanation
Answer: A. should Should gives advice and takes the base verb with no to.
You ___ to rest after the journey.
Show answer and explanation
Answer: B. ought Ought to always keeps to before the base verb.
You ___ go to bed early; you look tired.
Show answer and explanation
Answer: C. should Advice for the present uses should plus the base verb.
The train ___ arrive at six, according to the timetable.
Show answer and explanation
Answer: D. should Should expresses an expectation based on a plan or a timetable.
___ I open the window?
Show answer and explanation
Answer: A. Should Questions take should, while ought to is rare in questions.
You ___ eat so late; it is bad for your sleep.
Show answer and explanation
Answer: B. shouldn't The negative of should is shouldn't plus the base verb.
You ___ have booked earlier; the hotel is full.
Show answer and explanation
Answer: C. should Should have plus the past participle criticises a past action.
You ___ to have booked earlier.
Show answer and explanation
Answer: D. ought Ought to have criticises the past in a formal register.
We ___ better leave now, or we will miss the train.
Show answer and explanation
Answer: A. had Had better warns of a bad result if the advice is ignored.
Passengers ___ wear a seatbelt. It is the law.
Show answer and explanation
Answer: B. must A legal rule is stronger than advice, so must is correct.
You ___ drink more water in hot weather.
Show answer and explanation
Answer: C. should Should gives health advice with the base verb drink.
The parcel ___ arrive tomorrow.
Show answer and explanation
Answer: D. should Should expresses an expectation about the future.
___ we invite them to dinner?
Show answer and explanation
Answer: A. Should Questions use should before the subject, with no to.
You ___ worry so much about the exam.
Show answer and explanation
Answer: B. shouldn't Shouldn't is the negative form with the base verb worry.
She ___ to apologise for being late.
Show answer and explanation
Answer: C. ought Ought keeps to, so ought to apologise is the correct pattern.
We ___ have taken a map; we got lost.
Show answer and explanation
Answer: D. should Should have criticises the past decision not to take a map.
This medicine ___ be taken twice a day.
Show answer and explanation
Answer: A. should Should plus the passive be taken gives a recommendation.
"You ought to rest" means almost the same as ___.
Show answer and explanation
Answer: B. you should rest Ought to and should both give advice, so their meanings are nearly the same.
You ___ have told me you were coming!
Show answer and explanation
Answer: C. should Should have plus the participle criticises a past action.
He ___ to be more careful with his keys.
Show answer and explanation
Answer: D. ought Ought takes to, so ought to be is the correct advice form.
Drill complete
You answered every question.
Next topic: Past modals of deduction: must have, might have, can't haveTake the level test
Questions learners ask
What is the difference between should and ought to?
The meaning is nearly identical: both give advice and express expectation. The difference is form and tone. Should is shorter, more common and easier in questions and negatives. Ought to keeps the to and sounds slightly more formal, so it appears more in writing than in speech.
Why does should not take to?
Should belongs to the group of modal verbs, which take the base verb directly: can go, must go, should go. Ought is the exception among them because it always keeps to. Treat the patterns separately and the question of why matters less.
How do I criticise a past action politely?
Use should have plus the past participle: "You should have told me." The criticism lands on the earlier action, not on the person. Ought to have works the same way but sounds more formal: "You ought to have told me." Both are softer than an accusation.
More grammar topics
Past modals of deduction: must have, might have, can't have
Must have shows certainty, might have shows possibility and can't have shows impossibility about the past. All three take have plus the past participle.
Verbs followed by a gerund: enjoy, avoid, suggest
A group of common verbs takes an -ing form after them: enjoy, avoid, suggest, finish, practise and mind. Learn the group as a fixed pattern.
Verbs followed by an infinitive: decide, hope, promise
Many common verbs take to plus the base verb after them: decide, hope, promise, want, need and plan. Some also need a person before the infinitive.
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