HAVE TO AND MUST

https://youtu.be/_BW-8ob18gw

Must and Have to in the affermative and interrogative forms are used to speaking of obligations and responsibilities. Sometimes they can be used interchangeably, but the general rule is that contraddistigue

HAVE TO

It used to speak of obligations or responsibilities imposed from outside, Che not depends from who's talking - Is it necessary.

DON'T HAVE TO

Do not have to is used to express something that is not necessary .but 'possible to do if desired, it is not an obligation. .do not have to is flexible as to have.

MUSTIt must is used to talk about personal requirements in a manner similar to Should, but stronger. It is used when the decision to do something is taken by the speaker or the order is given by the speaker. It must is used in everyday situations when something important happens and requires immediate action. must only works in this form. Examples: "I must do the shopping now." "You must see this film!" "You must read this book by the end of the week.""Must you leave so early?"

MUSTN'TMust not it is used to express something that is prohibited. The rule says that you use it when the requirement comes from the speaker. The use of Should similar too, but stronger.