Como dizer "não é?" em inglês

Know that very end of a sentense where we ask for a confirmation of what we just asked? I'll give na example:

Essa é uma boa ideia, não é?
Você concorda comigo, né?

This part in bold and undelined. This little words I can't express correctly.
I'm used to say isn't but I don't know if it is right.

Somebody can help me?


And please, don't be shy to correct anything wrong I've sad.
I know I make a lot of mistakes when I try to express myself in english (while writing and speaking).
That's why it woult be great if someone help me to correct me.

Thanks!