turn it off 為何不是turn off it

首先，turn off是一個phrasal verb，解作關掉(機器/電器)。

那麼phrasal verb的句子結構是怎樣的呢？

1.如果object是一個普通的noun，放它在preposition的前或後皆可。
# Switch off the light.
# Switch the light off.

2.如果object是一個很長的noun phrase，就要放它在preposition的後面。
# Switch off the lights in the hallway next to the bedroom the president is sleeping in.

3.某些phrasal verbs限制object必須放在preposition的後面。
# The gas gave off fumes. (not *The gas gave fumes off.)

4.某些phrasal verbs限制object必須放在preposition的前面。
# They let the man through. (not *They let through the man.)

5.(適用於所有的phrasal verbs)如果object是pronoun，把它放在preposition的前面。
# Switch it off. (not *Switch off it.)
# The smell put them off. (not *put off them)
# They let him through. (not *they let through him)

回到你的句子：

1 .I turn off the alarm clock.√
I turn the alarm clock off.√
a. the alarm clock off只是普通的object。(上面的第1點)
b. turn off沒有限制object的位置。

2. Oh, I forgot to turn it off.√
Oh, I forgot to turn off it.×
a. object it 是pronoun。(上面的第5點)

您好，我推薦您一個非常不錯的英語學習網站，里面有很多非常不錯的學習資源，您能從中得到不少幫助：


http://www.hkenglishstudy.info


祝您好運!

(1) it is a phase (狀態) not a sentence.

e.g. "Turn off the light."

(2) in a sentence, we use turn it off .

e.g. Would you please turn the light off ?

e.g. I ' ll turn the TV off.

2010-01-21 10:49:01 補充：
e.g.

put the eggs into the box
point the gun at my head

至於off 應放在何處才适合,那就要看看off去形容verb or noun?


例1 : turn off the light. 在這句的off是作adv形容v=tern. [ 関 (off 掉) ]....那燈.


例2 ; turn it off. 在這句off是作adj形容pronoun=it. 換轉 [ 它 (off不工作的) ]
........take a [ day off. ] 休假一天......搵 [ 一天(off 離開/休息) ]

因為 it 是它, 我忘記了[把它關掉], also, in english, turn off it, does not make any sence, so in english we use turn it off,but not turn off it. Here are some EXs:

I don't know how to turn it off

Could you teach me how to turn it off?

Turning this off is hard


sorry that I use english, I am in USA now, and it is esay for me to explain in
english=)
hope this will help u ^^