Tag Questions are easy (a little easy). Answering them is a bit tougher.

There are basically 2 types of tag questions: positive and negative.  

Like this:

"You are American, aren't you?"  =  (I think you are American.  Is that right?)

"You aren't American, are you?"  =  (I don't think you are American.  Is that right?)

We use tag questions to confirm information that we think we know.  

You can change the verbs in sentences to use tag questions in many situations.  Like, "this isn't easy, is it?", or "you are getting frustrated, aren't you?".  Anyway, so far so good.  But a lot of people get confused on how to answer.  

Answer these:

1. The fire is hot, isn't it?     (I think the fire is hot)
2. The fire is cold, isn't it?     (I think the fire is cold)
3. The fire isn't hot, is it?     (I think the fire isn't hot)
4. The fire isn't cold, is it?     (I think the fire isn't cold)

How was it?  Could you answer all 4 questions without getting confused?  Let's see.  The best answers should be:

1. Yes, it is.     (agreeing)    
2. No, it isn't!     (disagreeing)
3. Yes, it is!     (disagreeing)
4. No, it isn't.     (agreeing)

I put #2 and #3 in bold type to show that you are disagreeing with me.  Please you a strong voice and shout out that I am wrong!