do u'll remember that in the 6th book hagrid talks about the argument between snape and dumbledore he overheard

what was the argument about?
pesonally i feel it was about dumbledore trying 2 convince snape 2 act as if he is killing him.
do u'll remember non verbal spells
may be snape has said avada kedavra but what if he is thinking about another spell


please tell me ur views

its important