Maybe, the compound word, is an adverb meaning "perhaps" or "possibly." Example: Maybe I will go out tonight. May be is a verb phrase meaning "might be" or "could be." Example: I may be going out tonight.

maybe = adverb (perhaps) may be = verb "may" + be

May be means it is a verb or action and it has two words 'May" and " be" Eg: May be I am wrong. Maybe is an adverb..meaning, anything that is not certain! Similar to "perhaps" Eg: I maybe going to the party