The words may be, maybe (2 words/1 word) sound the same but have different meanings and spellings. Why do may be, maybe (2 words/1 word) sound the same even though they are completely different words?
The answer is simple: may be, maybe (2 words/1 word) are homophones of the English language.
Common misspelling of maybe.
Informal An uncertainty: There are so many maybes involved in playing the stock market.
Informal An uncertain reply: It's better to receive a fast and honest no than a drawn-out maybe.
Definitions from Wiktionary, Creative Commons Attribution/Share-Alike License, from The American Heritage® Dictionary of the English Language, 4th Edition and Wordnik.
Homophones (literally "same sound") are usually defined as words that share the same pronunciation, regardless of how they are spelled.