Must vs Have To / Has To
Must and have to express obligation or necessity:
The main differences between must and have to are:
Must expresses an obligation forced by the speaker.
Have / Has to expresses general obligations. When we are talking about another person's obligation we use have to, too. We use have to when the obligation comes from outside. See the Exercise.
Teacher : You must listen to me carefully.
Father : You must stop smoking.
You have to put on uniform at school.
She has to buy new dictionary for school.
You have to give your report by 5 p.m. tomorrow.
They have to wake up early in the morning.
|Affirmative Form||Subject + must + verb + complement|
|You must come home before 8 o'clock.|
|Negative Form||Subject + mustn't + verb + complement|
|You mustn't come home before 8 o'clock.|
|Question Form||Must + subject + verb + complement ?|
|Must you come home before 8 o'clock?|
|Negative Question Form||Mustn't + subject + verb + complement ?|
|Mustn't you come home before 8 o'clock?|
HAVE TO / HAS TO
|Affirmative Form||Subject + has to / have to + verb + complement|
|He has to take his medicine.|
|Negative Form||Subject + don't have to / doesn't have to + verb + complement.|
|He doesn't have to take his medicine.|
|Question Form||Does / Do + subject + have to + verb + complement ?|
|Does he have to take his medicine?|
|Negative Question||Doesn't / Don't + subject + have to + verb + complement ?|
|Doesn't he have to take his medicine?|
When we say he doesn't have to take his medicine, we mean that he is not obligated to take his medicine. (Lack of necessity)
We say he mustn't take his medicine to give it a negative obligation meaning.Note:
Must is only used in present and future meanings. Have to can be used in any tenses.Note:
Must also has a probability meaning.
He missed the class for the first time, he must be ill.