Choose the correct answer

The boy has done it before, 

You are not going home, 

The girl speaks well,

Let's go, 

Our teacher left an hour ago,

A question tag is added to 

If the statement is positive, the question tag must be negative.

If the statement is negative, the question tag must be negative.

In question tag, the auxiliary verb in the statement must be used in the tag.

Which of these is a good response to a question tag

You are my friend, aren't you?

I am not going with you, am I?

Question tag is easy,