The mechanism that allows you to feel is broken

I’m not a huge fan of grammar pedantry, but I loved this exchange from Kiss Kiss Bang Bang. (Delivered by SWOON Michelle Monaghan)

Harry: I’m interrupting. I feel badly. What are you drinking?

Harmony: Bad.

Harry: Bad? Sorry?

Harmony: You feel bad.

Harry: Bad?

Harmony: “Badly” is an adverb. To say you feel badly says that the mechanism which allows you to feel is broken.

Kiss Kiss Bang Bang really is one of the great underrated films.