 today. This is Marc. I'm doing just great. Thanks for asking. You have to be quiet during a lecture at university or you must be quiet during a lecture at university. Evil has to be the reason for such deaths or evil must be the reason for such deaths. Students have to learn English for their future career or students must learn English for their future career. In this lesson we're going to look at the difference between have to and must. So stay tuned. Let me tell you first that have to is used mostly in American English. Must is used also in American English but on property science. For example you will see that are written. Visitors must report to admission offices for example. Must is slowly disappearing from the language. So is 50% less used now than in the past. So is slowly disappearing from the language. They're both modal verbs and they follow the following rules. So we have to the positive sentence would follow the following formula. Subject plus have to plus the base of the verb plus the object and then the time expression if any. With must instead the formula goes subject plus must plus the base of the verb plus object and then the time expression if any. Now this is easy. Remember that must we don't need to. This is one thing to remember. When we write a negative sentence instead we need the subject plus the auxiliary plus not the auxiliary of the tense we are using in this case. So we could be do, does, did or will etc plus have to plus the base of the verb plus object and then the time expression. If we use it in a negative sentence have to it means no obligation or necessary. Instead if you use must in a negative sentence the formula would be subject plus must plus not plus the base of the verb plus the object and then the time expression if any. And in this case if you use must in a negative sentence it means prohibition. I will give you two examples. So the first one would have to. You don't have to call me before coming over. It's not necessary. This is what I'm saying. With must instead you mustn't drink bleach. It'll kill you. So you cannot you're not allowed or you it will it will kill you anyway if you drink bleach. So you mustn't. Now let's go on with it with interrogative sentence. So we need WH question word if any. So WH question word would be where, who, how, what etc. Then we need the auxiliary then the subject then have to and then the base of the verb and maybe the object of time expression in a question. So it depends here. It would change. If you want to watch a lesson on making questions you can click here. For an interrogative sentence with must you have to use WH question word if you have one then must then the subject then the base of the verb and then the time expression or object if any. This is very very rare okay we we usually don't use it in a question. Okay now the most important thing is when and how we use these two. The first rule is use the monover have to to express strong obligation. This strong obligation is based on a rule or law and obviously have to is impersonal. So somebody else tells you to do something impersonal. Instead must we use it to indicate a personal so personal recommendation. Now I have two examples and let me show you the two examples that I wrote. These are the examples that I gave you at the beginning and the first one we have to is you have to be quiet during a lecture at university I said. In this case have to is a strong obligation right. I'm telling you because you cannot speak during a lecture at university. Instead if I say you must be quiet during a lecture at university this is a recommendation I'm saying to someone okay this is the difference. Then another difference or another usage of have to is to say how likely something is and in my example in the introductory example was evil has to be a reason for such deaths has to be the reason and this is likely so it's probable that evil was the reason for such deaths. Instead if you use it with must use must to express convention or certainty about something so evil must be the reason for such deaths. So I'm convinced that evil was the reason for such deaths. Now the third usage is for have to to indicate that it's important to do something. For example the the the introductory example was students have to learn English for their future career. By this example I'm saying that it's important for students to learn English for their future careers. Instead if I use it with must indicates a necessity so students must learn English for their future career so it's necessary for students to learn English for their future career so you can see that it changes meaning. They can be both used with the past so the past of have to is had to remember that if you make a question or a negative sentence you need did for the past right of have to. Now instead if you use must with the past it would be must have plus past participle. For the future in the have to we have will have to so I will have to do something next week for example so it is used for the must we don't have future and so we use have to and one last thing that I want to say about have to is that you can use have got to in British English instead of have to is the same thing. Now let's recap so in this lesson we talked about the difference between have to and must have to is used for a strong obligation instead must is for necessity certainty or personal recommendation so use have to for a strong obligation based on a rule a law imposed by an institution or by somebody must instead is personal and is used in the present and in the past in the future we just used have to that's it for today thank you very much for watching if you have any comments requests or if you want to write your own example using both have to must you may do so under this video please don't forget to share the lesson if you liked it and don't forget to subscribe to my channel if you haven't have a great day and see you next week with a new lesson take care bye bye