Standard Chinese translation of "I'm not a bad person"

Question

I'm trying to translate "I'm not a bad person" to standard Chinese. I am told the following:

There are also two ways to say "A isn't B". When B is a noun (things, people, places, etc.), use bú shì.

It seemed to me that B here is "bad", which is an adjective. So I said that the translation would be "wô bú huài-rén". The only other option would have been to add "shì".

But I was told that this is incorrect. It seems to me that I followed the information correctly, no? Did I do something incorrectly, or are the instructions incorrect?

Thank you.

Answer 1

B is person, which is a noun. So you should use 不是. Bad is an adjective and it's used to modify person, so the translation should be

我不是一个坏人。