When we reply to a statement we can put an affirmative or negative tag at the end of our comment. This short tag takes the form of a question. An affirmative comment has a negative tag and a negative comment has a positive tag.
It’s a wonderful piece of music. → Yes, it is, isn’t it. He runs very well. → Yes, he does, doesn’t he. They were all happy with the result. →Yes, they were, weren’t they. It’s not a nice day for swimming. →No, it isn’t, is it. They weren’t happy with the food. → No. They weren’t, were they. She’s become very attractive. → Yes, she has, hasn’t she. They haven’t been very helpful. → No, they haven’t have they.
We can also put a short tag at the end of a statement: It’s a wonderful piece of music, isn’t it? He runs very well, doesn’t he? They weren’t happy with the result, were they? She’s become very attractive, hasn’t she?
We use ‘so’, ‘neither’, ‘not either’ or ‘nor’ when we add more information to what someone says: I love Belgian chocolate. → So do I. My sister’s living in Birmingham. → Really, so is my cousin. They’ve decided to move to London. → So have we. She doesn’t like American comedies. → Neither do I./I don’t either. I haven’t been to the cinema in ages. → Nor have I. We won’t be able to go to the concert. → Neither will we.