かもしれない

Maybe/possibly
Plain Form Verb/Noun/い Adjective + かもしれない
な Adjectives: drop な + かもしれない

かもしれない is かも (which means question mark) + しれない (negative potential form of 知る) . It means “maybe” “might” or “possibly”. かも is a particle that can go directly after a noun or な. This phrase is very common in Japanese. 

Examples

• 食べたかもしれない – Might have ate (something). 
• 学校に行くかもしれない – Might go to school.
• トイレに行っているかもしれない – He might be in the toilet
• 男かもしれない – It might be a guy
• 楽しいかもしれないよ – It might be fun.

Other Forms

かもしれない may alternatively appear as かもしれません or be abbreviated to かも。

• 食べたかも – He might’ve ate. 
• 薬は効くかもしれません – The medicine might work.