Student or Learner
"I'm trying to teach them something" "And how's it going?" "Pretty well" or good.
I think "well" is correct?
I didn't know that both are correct?
It's going pretty well. - This is correct, though in colloquial or informal American English, you'll hear people say "good" as a reply to this question. This is probably so because "How's it going?" can be taken to mean "How are you?", and it is correct to say "I'm good" as a reply to "How are you?"
good: Definition, Synonyms from Answers.com