now可用作副词，表示现在，马上，此刻。用作名词时，有现在，此刻的意思；用作形容词时有现在的，目前的等含义。
一.now用作副词，表示现在，马上，此刻。
You've got to ask him.It's now or never.
你得去问他,机会难得。
Until now she has never been to see a doctor.
到目前为止她还没有去看过医生。
二.now用作名词，表示现在，目前。
The boss is being in royal spirits right now.
此刻，老板情绪极好。
Now he slept quietly with his fathers.
此刻他安静地躺在祖坟中。
三.now用作形容词，表示现在的，当今的。
She had now a life filled also with a beneficent activity.
她目前的生活里善行颇多。
Now, a living language has been found that can play the same intermediary role more successfully.
最近，已找到了一种现存的语言，它能更有效地起到中间媒介的作用。
四.now在句中除作状语外,还可作主语、表语或介词宾语。
