Here is a note that I received recently from a professional colleague.
One set of word usages that I have found confusing for non-English speakers (and even for English speakers if they think about what they are saying) is the use of “pretty” and “awful” as adverbs. We sometimes say something is pretty bad or pretty good. Someone can be pretty sorry or pretty smart . Similarly something could be awful bad or awful good or I could be awfully sorry or awfully smart. I think pretty bad is not as bad as awful bad, but is pretty smart better or worse than awfully smart? Even more interesting is something could be pretty awful or awfully pretty—and these are really different.