Understanding how to express past obligation or advice in English is essential for effective communication. One of the modal verbs used in this context isought to. While learners are often familiar with using ought to for present or future advice, many wonder how to use itspast form. Though ought itself does not change with tense, the structure of the sentence must be adjusted to reflect past time. This topic explains how to form and use the past form of ought to, with examples and comparisons to similar modal expressions like should have.
What Does Ought To Mean?
Ought to is a modal verb used to express
- Advice or recommendation
- Duty or obligation
- Expectation or probability
Examples in present/future
- Youought toapologize to her. (advice)
- Theyought toarrive soon. (expectation)
Can Ought To Be Used in the Past?
Yes, ought to can express something that was expected, advisable, or obligatory in the past but it requires a change in sentence structure. The verb ought remains the same, but the construction uses the perfect infinitivehave + past participle.
This is similar to how should is used in the past.
Structure of the Past Form
The structure for using the past form of ought to is
- Ought to have + past participle
Examples
- Youought to have toldthe truth.
- Sheought to have finishedher homework by now.
Usage of Ought to Have
Expressing Regret or Missed Obligation
This structure is commonly used to express regret or criticism about something that did not happen in the past, but should have.
Examples
- Weought to have leftearlier to catch the train.
- Heought to have apologizedfor his behavior.
Positive Statements
Use ought to have + past participle to indicate that someone was expected to do something in the past, and it would have been the right or wise action.
- Theyought to have listenedto the teacher.
- Sheought to have checkedher work before submitting it.
Negative Statements
In negative sentences, the correct structure is
- Ought not to have + past participle
Examples
- Youought not to have spokento him that way.
- Heought not to have wastedso much time.
Questions with Ought to Have
To form a question, ought comes before the subject.
- Ought she to have informedthe manager?
- Ought they to have returnedthe book?
Note These structures are grammatically correct but sound formal. In casual English, should is often preferred in questions.
Comparison Ought to Have vs Should Have
Ought to have and should have are very similar and can usually be used interchangeably. Both are used to talk about something that didn’t happen in the past, but would have been the right thing to do.
Examples
- Youought to have studiedmore for the test.
- Youshould have studiedmore for the test.
In terms of tone, ought to have may sound slightly more formal or emphatic, but the meaning is largely the same.
Common Expressions Using Ought to Have
Here are a few expressions where ought to have is commonly used to talk about the past
- Youought to have knownbetter.
- Iought to have calledyou yesterday.
- Weought not to have ignoredthe warnings.
- Sheought to have beenmore careful.
Grammar Tips for Learners
- Always follow ought to with the base verb, and use ought to have with the past participle.
- In negative form, use ought not to have, not didn’t ought to.
- Don’t forget that this structure is used to talk about thepast, not the present or future.
Correct vs Incorrect Usage
CorrectSheought to have calledher parents.
IncorrectSheought had calledher parents.
CorrectWeought not to have donethat.
IncorrectWedidn’t ought to dothat.
Practice Exercises
Convert the following present statements using ought to into their past forms using ought to have.
- You ought to help him. → __________
- She ought to speak politely. → __________
- They ought not to lie. → __________
Answers
- Youought to have helpedhim.
- Sheought to have spokenpolitely.
- Theyought not to have lied.
Summary Table
| Form | Usage | Example |
|---|---|---|
| Ought to + base verb | Present or future advice | You ought to be careful. |
| Ought to have + past participle | Past advice or regret | You ought to have been careful. |
| Ought not to have + past participle | Negative past advice | You ought not to have done that. |
While the verb ought doesn’t change with tense, using it to talk about the past involves a specific grammatical constructionought to have + past participle. This form allows English speakers to express regret, advice, or expectation about past events. Though sometimes replaced with should have in casual speech, ought to have remains grammatically correct and useful in both spoken and written English. Mastering this form not only improves your accuracy but also adds depth and variety to your communication skills in English.