maybe my replay is be waste cause its too old topics
but I will write the answer as one Japanese.
first, different of が or を
(で is a tool sentence I shot him with gun. わたしはgunでhimをhit not difficult)
水を飲みたい
I wanna drink water(but other drinks OK) thirthty
水が飲みたい
I wanna drink water(I love water...