ad.

1. 再，再一次
   Would you say that again?

   请你再说一遍好吗？

2. 重回；恢复原状
   Henry was glad to be home again.

   亨利很高兴又回到家里。

3. 再者；此外
   Then again, I doubt whether he will come.

   再说，我怀疑他是否会来。

adv.

1. once more.
2. returning to a previous position or condition.
3. in addition to what has already been mentioned.
   ▸on the other hand.