What Is Their Main Difference?
Talking about Obligations
We use 'have to' and 'ought to' to talk obligations. Obligations are motivated by law, someone, or oneself. 'Ought to' is less common and more formal than 'have to.' Have a look:
We can use 'have to' and 'ought to' in affirmative form by placing them before the main verb. Watch:
To create the negative form of 'have to' and 'ought to' we follow the patterns illustrated below:
- do/did/does + not + have to
- ought + not + to
To create questions with 'have to' and 'ought to,' we use the patterns shown below:
- Did/Do/Does + subject + have to + main verb + …?
- Ought + subject + to + infinitive + …?