It's a tag question, innit?

Tag questions are a kind of yes-no question used when you want to confirm that something is true. They are formed by attaching a question tag to the end of a declarative sentence. Here is one example:

He is in jail, is he?

Notice that the tag "is he" has the same form as the beginning of a normal yes-no question that you would use if you didn't have any idea about the answer:

Is he in jail?

I DO TOO and I DON'T EITHER

Use too with a positive sentence:

A: I like chocolate.
B: I like chocolate too!

Use either instead of too when the verb is negated:

A: I don't like chocolate.
B: I don't like chocolate either!

A: I've never liked chocolate.
B: I've never liked chocolate either!

Notice that the form of tag questions also depends on verbal negation:

I like chocolate, don't I?
I don't like chocolate, do I?