Asking whether you or others have an obligation to do or not:
Do I have to do it now?
Do I need to leave her a message?
Must I accept the request?
I don’t have to attend the meeting, do I?
Do you have to get to the office so early?
Are you expected to finish the job by tomorrow?
Must you work so hard?
Is it necessary for me to go with them?
I must tell them the true.
I must do everything I can to help you.
I have to send the report today.
I have to be there by tomorrow.
I have to go now.
I’ll have to pick her up from the airport.
It is necessary that you follow this guideline.
I can’t refuse to do that.
I can’t avoid it.
It is my responsibility to clear the table.
It’s my duty to do it.
I have no other choice.