Responsibilities and Obligations
Must and Have to
Must - Strong Personal Obligation
Use 'must' in the positive form to speak about strong personal obligations that you feel are crucial at the moment of speaking.
I must try this weight reduction program.
I must follow the documented food service policy.
Have to - Responsibilities
'Have to' is used to indicate responsibilities at work. Use 'have to' to talk about daily responsibilities and obligation in general. 'Have to' is often confused with 'must'. The main difference is that 'have to' expresses obligation to work, family, friends, etc. 'Must' is used to indicate strong personal obligation that is felt at the moment of speaking.
'Have to' differs from other modal forms. 'Have to' is conjugated and followed by the base form.
Positive Form:
Waiters have to use problem-solving skills during the lunch rush.
Negative Form:
Your restaurant doesn't have to provide rolls and breads for free.
Question Form:
Does it have to be a team effort?
Had to
When speaking in the past, there is only one way to express obligation: 'Had to' We use 'had to' when we speak about past responsibilities and strong personal obligations.
Example:
Bob had to go through all three management training programs when he was promoted.
Bob had to sweep the floor of the cafeteria after closing last week.
Must vs. Have To
'Have to' expresses everyday responsibilities at work, or for family and friends. 'Must' is only used for strong personal obligations.
Example 'Have to' for Responsibilities:
We have to teach our class on hotel operations on Tuesdays.
Waiters have to use problem-solving skills during the lunch rush.
Example 'Must' for Strong Obligations:
I must try this weight reduction program.
I must follow the documented food service policy.
The difference between 'have to' and 'must' in the negative is extreme. 'Not have to' signifies a lack of obligation. 'Mustn't', on the other hand, signifies prohibition. The past form of both 'must' and 'have to' is 'had to'
Example 'Have to' for No Obligation:
Peter doesn't have to fly first class to get to the conference next week.
Your restaurant doesn't have to provide rolls and breads for free.
Example 'Mustn't' for Prohibition:
Pedestrians mustn't be allowed to use the drive-in service.
One mustn't give up quality for convenience.