“At” vs. “in” before verb
"He is good in painting" or "He is good at painting" — which one is correct?
English Language & Usage Stack Exchange is a question and answer site for linguists, etymologists, and serious English language enthusiasts. It only takes a minute to sign up.Sign up to join this community
There's only one major case that leaps to mind where "good in" is idiomatically correct:
He is good in bed.
This can be generalized somewhat to "he is good in (location where certain stereotypical activities are performed)", like saying "he is good in the field" to mean he is good at doing the tasks that need to be done in the field.
He is good at painting.
He is good in painting.
is definitely incorrect — I’ve heard this form from non-native speakers, but never I think from native speakers — but its meaning is still clear; it doesn’t risk confusion.
This goes equally for any verb or activity: she is good at climbing, he is terrible at football, I am not very good at stand-up comedy are standard, and would be incorrect with in. I can’t think of any idiomatic exceptions.
I recently found it "The key to you for a successful class will depend in most part by how good you are in listening, questioning, note taking and studying and most important, test taking.