吗【ma】

吗 at the end of a statement turns it into a yes/no question. Nothing else in the sentence moves.

English inverts the subject and verb to ask; with 吗 the statement keeps its word order.

• × 是你学生吗？ → 你是学生吗？

Answering

There's no single word for "yes". Repeat the verb to agree, and negate it to disagree: 是 or 不是, 有 or 没有, 去 or 不去.

Not with question words or A-not-A

A sentence that already asks with 谁, 什么, 哪儿, 怎么 or an A-not-A form takes no 吗.

• × 你叫什么名字吗？ → 你叫什么名字？
• × 你是不是学生吗？ → 你是不是学生？

With 吗 added, 什么 and 哪儿 stop asking and mean "anything" and "anywhere".

吗 is toneless and adds no politeness; the question is neutral. 吧 in the same place asks you to confirm something the speaker already thinks is true.