 Have to or must, the differences. Have to and must are both used to show that something is necessary, but there are some differences. Let's understand how to use these words with some with natural English examples below. The two expressions have to and must both show that something is necessary, but there are some differences. Have to can be used in the past tense, had to do something, while must can not. The negative forms have a different meaning. It's not do does, not equal don't have to do. Have to do is more commonly used in North America than must do. Have or has to do. If we have to do something, it means it is necessary and we are required to do it. For example, Lucy has to work this Saturday. Tim broke his arm on Tuesday. He had to go to the hospital. I have to finish my essay today or my teach will be angry. Must do must can be used in the same way as have to such as here. It's getting late. I must go equals it's getting late. I have to go must can be used to give your opinion or recommendation. I watched that new sci-fi movie last night. It's great. You must watch it. I'm having a big barbecue party this weekend. You must come. Thanks so much for watching. We are ITTT the leading provider for TEFL and TESOL training courses. If you like this video, please subscribe by clicking that button down here and click on any of the videos here on the left for more interesting teaching tips for getting certified to teach English abroad and online.