Have you ever heard such a conversation?
–How are you doing?
-Good.
Oops… Do is a verb, logically, we got to use WELL here…
Yep. it’s American English and they often use GOOD as a verb. So, don’t roll your eyes when you here:
I’m doing GOOD.
How’s it going? GOOD.
And if you’re gonna live in the states, use the same phrases to blend in.