All of these words are very similar in their meanings. "Should" and "ought to" are basically the same word, the only difference is "should" is used more often. For example: "You should (ought to) close the refrigerator door." This means you don't /have/ to close the door, but it would be better if you did. "Must" means the same as "have to." If you say "You must (have to) close the refrigerator door," this would mean that you have no other choice. You can't leave the door open, you can do nothing but close the door. Here, "have to" is more common. "Might" and "may" can mean the same thing, but may has more than one meaning depending on the context. "James may/might close the refrigerator door," means that James could close the door, or he could not. Nobody knows because the action hasn't happened yet, so we use "may." An example using the other meaning of may is "May I close the refrigerator door?" In this sentence, the person is asking for permission to close the door. I hope this isn't too much haha. If you have any questions, I'll be happy to answer them. Happy studying!

should = this is my advice ought to = this is the best thing to do/is very important (stronger and more formal than should) must = you are obligated to do this or you have a very strong need to do it You should tell him you are sorry. You ought to ask him what he thinks. You must remember to take out the trash. may = gives permission/expresses possibility might = expresses possibility, vary rarely used for permission now-a-days You may go home now. You may be able to get a scholarship. You might be able to get some more training. I hope this was helpful for you. If you need more explanation and practice, please take a look at my profile or look for me on the Instant Tutoring page.

I am not a native English speaker, so I don't know if my answer is 100% accurate. Maybe someone else will explain it better :) "Should" and "ought to" should be almost the same, don't worry about them. "Should" is used more often. "Must" and "have to" are also very similar. There is only a small difference: "Must" means something you do because you want to, "Have to" means something you do because something forces you to. Example: A mother and a son go to the church every Sunday. The mother is a Christian, but the son hates the church and only goes there because his mother tells him to. The mother MUST go to church, but the son HAS TO go to church. More examples: "I must study every day." I believe it helps me, and I decide to study every day because I want to improve. "I have to study every day." There are lots of hard tests, I will fail if I don't study. Also, you can use "must" to talk about assumptions. "You are an actor? That must be a fun job!" This means: "I don't know if it is a fun job, but I assume it is!". "May" and "might" are very similar, but there is a small difference in probability. "This may happen." - Normal. "This might happen." - I think it will not happen. The probability is under 50%. Also, people often use "can" instead of "may", it sounds more modern. Hope this helps! 頑張ってねぇ！

must is strong like obligation

"should "- supposed to do it (but they can't make you) I should go to bed now, because I have to get up early. He should tell her how he feels. "ought to"- would be best to do it (but this phrase is rarely used in the USA). "must "- one definition is required.=have to, (not used very often in the USA, but when used it is often used as a motivation or encouragement word): I know you don't want to go to work, but you must. (emphasis on "must" to motivate the person) I hate writing essays, but I must (emphasis on "must" to motivate myself) The other is used to describe a deduction (problem solving) that has been made: I must be crazy to believe what he is saying. I must have left my book on the bus. I had it this morning, but it is not in my bag. He must be lonely now that his family is on vacation out of town. (this is how must is used most often in the USA) "have to"- required. =must, but more common in conversation -I have to go home now (or I will get in trouble). -I have to go to work tomorrow (or I will be fired). -I have to go to school now (or I will be marked absent). I showed in parentheses ( ) why this is "have to" "may" - one definition is the person could choose (to do or not to do) The other involves permission "might" Choose: She may not feel that way (she may feel differently than we think). She may stay at school (I don't know what she is choosing to do). I may not go to school tomorrow (I am not feeling well and may stay home instead). Permission: Mother, may I take five baby steps? (this is a game that helps children remember to say "may") May I have another cookie (asking permission). Yes, you may go outside now (a parent giving permission).