1）maybe是副詞,意為“也許,大概”.它通常放在句子的開頭,在句子中作狀語.如：
Maybe they won't come here tonight.他們大概今晚不會來這兒.
Maybe she is happy.也許她是幸福的.
2）may be是情態(tài)動詞may加動詞原形be構(gòu)成的,在句中做謂語,意為“可能是、大概是”,后接形容詞、介詞短語或名詞作表語.如：
She may be at home.她可能在家.（也可以說：Maybe she is at home.）
You may be right.你可能是對的.（也可以說：Maybe you are right.）
所以改為 may be