Here are a few examples: You may come for dinner. (This is an offer for you to come to dinner if someone is talking to you.) She may come for dinner. (This could either mean she might come [if she is available or she wants to] or someone is letting someone else know that she may come to dinner [allowing her to come]) I might come to dinner. (This can only mean that they may show up for dinner—they are already allowed to come) I also like to think that "might come" means that it is less likely that I will show up versus "may come" where it is more likely I will be there. Hope that helps : )