[nǎi]
[動(dòng)]
（是； 就是； 實(shí)在是） be; be really; be indeed
Failure is the mother of success.
失敗乃成功之母。
[副]
（于是） so; therefore; hence
It was a steep climb, so we rested for a while halfway up the hill.
因山勢高峻，乃在山腰休息片時(shí)。
（才） only then
I didn't know it until now.
今乃知之。
You can make progress only if you are modest.
惟虛心乃能進(jìn)步。
[代]
（你； 你的） you; your
your father
乃父