1）maybe是副词,意为“也许,大概”.它通常放在句子的开头,在句子中作状语.如：
Maybe they won't come here tonight.他们大概今晚不会来这儿.
Maybe she is happy.也许她是幸福的.
2）may be是情态动词may加动词原形be构成的,在句中做谓语,意为“可能是、大概是”,后接形容词、介词短语或名词作表语.如：
She may be at home.她可能在家.（也可以说：Maybe she is at home.）
You may be right.你可能是对的.（也可以说：Maybe you are right.）
所以改为 may be