In this case you could say: It might be him. Maybe. Maybe is usually one word when used alone. There isn't much difference at all. But if there is a difference, I feel 'may be' is less positive than 'could be'. Eg: a: Is that him? B: it could be. (Sounds more hopeful or positive it is him). If B said 'maybe' or 'it might be him', it feels more vague. Like B thinks it's probably not the person. They are a lot more unsure. I hope this helps.

The differences between may be, might be, and could be Hi. We can use may, might and could to express the idea of possibility. Then, what are the differences between may be, might be, and could be? If I had gone to the University of Miami, I could have participated in their Spanish immersion program. In this sentence, can I use "may have" or "might have" instead of "could have"? Thanks for help.