呢【ne】

呢 attached to a noun asks the question that was just asked, about someone or something else. The rest of the sentence is left out because it has already been said.

What 呢 carries over is the last question or statement. On its own, 你呢 means nothing; after 你叫什么名字 it means "and what's your name?".

Asking where something is

Noun + 呢 with nothing before it asks where that thing has gone.

呢 does not make a yes/no question

nǐ你shì是xué sheng学生ne呢 is wrong. For that, use 吗. 呢 either follows up on an existing question or attaches to a question word.

Here 呢 softens the question rather than asking it – 哪儿 does the asking.