Questions Ending with 吗(ma)
When 吗 is added to the end of a declarative statement, that statement is turned into a question. To answer the question in the affirmative, drop the 吗 from the end of the question; to answer the question in the negative, drop the 吗, and insert a negative adverb before the verb.
A: 你是学生吗?
B: 我不是学生。
A: 你是学生吗?
B: 我不是学生。