名詞 now:

1. the momentary present

副詞 now:

1. at the present moment
   同義詞：at present
2. in these times
   同義詞：nowadays, today
3. in the historical present; at this point in the narration of a series of past events
4. (prefatory or transitional) indicates a change of subject or activity
5. used to preface a command or reproof or request
6. without delay or hesitation; with no time intervening
   同義詞：immediately, instantly, straightaway, straight off, directly, right away, at once, forthwith, in real time, like a shot
7. in the immediate past

1. It is now possible to put a man on the moon.
   目前已能將人送到月球上。
2. He is writing a letter now.
   他現(xiàn)在正在寫信。
3. He was at home just now.
   他剛才在家。

now

adv.（副詞）
At the present time:
現(xiàn)在：
例句：
goods now on sale; the now aging dictator.
現(xiàn)售貨物；現(xiàn)在正在衰老下去的獨(dú)裁者

At once; immediately:
立刻；立即：
例句：
Stop now.
立即停止

In the immediate past; very recently:
剛剛；最近：
例句：
left the room just now.
剛離開房間

At this point in the series of events; then:
在一系列事件的一點(diǎn)；那時(shí)：
例句：
The ship was now listing to port.
船當(dāng)時(shí)正向港口開進(jìn)

Nowadays.
如今
In these circumstances; as things are:
在這些情況中；正如事情是：
例句：
Now we won`t be able to stay.
這種情況下我們不能留下了

Used to introduce a command, reproof, or request:
用來引出命令、譴責(zé)或要求：
例句：
Now pay attention.
現(xiàn)在注意了

Used to indicate a change of subject or to preface a remark:
用來表示主語的變化或作為標(biāo)記：
例句：
Now, let`s get down to work.
現(xiàn)在，讓我們埋頭工作吧!

conj.（連接詞）
Seeing that; since:
因?yàn)?；既然?/br>例句：
Now that spring is here, we can expect milder weather.
現(xiàn)在春天來了，我們可以期望較溫和的天氣

n.（名詞）
The present time or moment:
此刻，現(xiàn)時(shí)：
例句：
wouldn`t work up to now.
到現(xiàn)在都不肯工作

adj.（形容詞）
Of the present time; current:
現(xiàn)在的；時(shí)下的：
例句：
our now governor.
我們現(xiàn)金的州長

Slang Currently fashionable; trendy:
【俚語】 現(xiàn)今時(shí)髦的；傾向的：
例句：
the now sound of this new rock band.
這支新?lián)u滾樂隊(duì)的流行樂曲

<習(xí)慣用語>now and again 或
now and then
Occasionally.
偶爾地
來源：
Middle English
中古英語
from Old English nô * see nu-
源自 古英語 nô *參見 nu-

【引伸】
now.ness
n.（名詞）