"You are talking a lot."
Translation:Vi parolas multe.
"Are" is tricky in English. Sometimes it's the main verb and sometimes it's just a helping verb. One rule of thumb is if you can replace "are" with something else, then you probably won't have "estas" in Esperanto.
- We are running - We run - ni kuras.
- We are singing - we sing - ni kantas.
If you can't replace it, then you need the estas.
- We are happy - Ni estas felicxaj.
- We are students - Ni estas lernejanoj.
So the difference between "diras" and "parolas" seems to be that "diras" always takes a direct object, that being WHAT is being said. "Parolas" instead refers to speaking more generally, and the only direct object it seems it can take is a language. See: I spoke (diras) a word vs I spoke (parolas) English, he talked (parolas) about food vs he told (diras) a lie