两者就词形而言,一分一合。就词性和词义而言,maybe是副词,意思是“也许、可能”,在句中作状语,相当于perhaps,常居句首。而 may be结构中,may是情态动词,be是动词原形,两者构成完整的谓语形式,与主语形成主系表结构,意为“也许是、可能是”。如:
He may be in the office.(may是情态动词)
=Maybe he is in the office.(maybe是副词)他或许在办公室。
Maybe she'll come this afternoon.她可能今天下午来。