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 object to the cash flow statement.
Due to current inflation we must put a control on our spending
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:
You have to give a down payment.
Negative Form:
You do not have to have any assets in order to secure a credit card.
Question Form:
They have to make a down payment of $20,000 on the house.
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:
We had to explain the specifics of the floating-rate loan before we could meet with them yesterday.
Susan had to revise the balance sheet 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 come up with paperwork and documentation for the audit.
The client has to use the call option by Monday.
Example 'Must' for Strong Obligations:
I must object to the cash flow statement.
Due to current inflation we must put a control on our spending
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:
You don't have to worry about that withholding tax.
You don't have to report the withholding tax on your year-end forms.
Example 'Mustn't' for Prohibition:
Leah mustn't write a bank draft for over one hundred dollars.
You mustn't throw the files away because the boss won't allow it.