Shall, Used to, Ought to
Is used to indicate future action. It is most commonly used in sentences with subject “I” or “We” and is often found in suggestion.
Example : Shall I call a doctor for you?
2. Used to
We use “Used to” for something that happened regularly in the past but no longer happens.
Example : Ben used to smoke a packet a day but he stopped two years ago.
3. Ought to
Is used to advise or make recommendation
Example : You ought to stop smoking.