Thanks your reply. I try to get what you mean here.
rolled in = the ball rolled into the drain first, and then rolled again, right? (It is wrong to say "rolled in" because the ball only rolled into the drain, and it couldn't roll again in the drain.)
The ball kept rolling into the drain. ( Is that mean " the ball continues rolling although the ball is in the d
Hi, rolled in = the ball rolled into the drain first, and then rolled again, right? (It is wrong to say "rolled in" because the ball only rolled into the drain, and it couldn't roll again in the drain.) It's not wrong, but 'into' is better, more clear. 'In' can mean both 'it entered the drain and stopped' or 'it entered the drain and kept rolling'.