'可以吗' (kěyǐ ma) is a polite, interrogative phrase meaning 'May I?' or 'Is it allowed?' It combines the verb 可以 (kěyǐ, 'to be permitted/able to') with the question particle 吗 (ma), which turns any statement into a yes/no question. Unlike English, Chinese doesn’t change word order for questions—adding 吗 at the end is sufficient. This phrase expresses deference and seeks permission rather than making a request outright.

It’s commonly used in everyday situations: asking to borrow something, enter a room, use a device, or change plans. The tone is soft and cooperative, making it appropriate for interactions with teachers, elders, colleagues, or strangers. While grammatically simple, its register is distinctly polite—using it shows awareness of social hierarchy and respect. It’s not typically used for urgent or commanding requests; for those, alternatives like '我能…吗？' (Wǒ néng... ma?) or imperative forms are more common.