例如這2句：

When he came, I was writing a letter.

While I was talking to you, you must be quiet.

請問上面2句可以用As來代替嗎? (As的連接詞用法)

謝謝你！

Hello Viceidol:

ha 你又出現了!!真高興.我又可以學到東西了!!因為每次when members(like you)ask English questions on the forum, then就會有一群熱心的帥哥and美女來解答.就在這一問一答的過程中學到了很多東西!!

[when]:-

1) = "at the time that"; "whenever"; "as soon as"
(當...的時侯; 無論什麽時侯; 一...的時候)
e.g. James pretended to be deaf when I spoke to him.
e.g. It is cold when (= whenever, 但語氣略輕) it snows.
e.g. He joined the army when (= as soon as) he returned home from Canada.

2) = "whereas"; "seeing that"
(可是; 而; 既然)
e.g. Why do you walk when you might ride a bicycle?
e.g. How can I bring Joseph to his senses when he will not listen?

3) = "if"
(如果; 要是)
e.g. You shall have the apple when you say "Please".
e.g. Come when you are ready.

4) = "表示同時性的時間從句"
(從句的主語和主句的主語一致時, 往往將從句的主語, 聯繫動詞, 或助動詞省去, 只留連詞, 意義動詞或表語, 或改寫為短語, 从突出重點。)
e.g. I'll do that only when necessary.
*e.g. Don't read WHILE eating.
e.g. When a boy, he liked to wander about the fields and woods.
*e.g. ON arriving in Shanghai, he telephoned me.

5) = **"at the same time"
("when, while and as" 可以在表示同時性的時候相換用, 意思是"在...的同時")
*e.g. The so-called tourist trembled AS he spoke.
*e.g. He went out (just) AS I entered.
*e.g. AS I was walking in the park, I heard a nightingale sing.

==========================================================

["while]:-
When 和 while 在表示時間上, while 不能指時間的一點, 因為 while 的含義是(以下所列):

1) = "at the same time that" (同時)
e.g. Please take it down in shorthand while I dictate.

2) = "for as long as"
e.g. I am safe while (= for as long as) I am here.

3) = "during the time that"
e.g. Please write while (=during the time that) I dictate.

4) = *"表示相反和對照 (opposition, contrast)" (而; 可是)
e.g. John imagined that the whole world knew of his achievement, while in reality only a few specialists had heard of it.
注意: 在表示對比時, 有些時候也可以用 when, 但總是會有時間的意味; while 則不一總是有時間的意味, 有時却有讓步的意味。
例一: (不能用 while)
>> The train had just started when we arrived at the station.
例二: (對比)
>> He walks when he might ride a bicycle.
例三: (含有讓步的意味)
>> While this is true of some, it is not true of all.

HTH.

Source: "A Dictionary of Modern English Usage"

對啊 這個版有很多很強的專家 謝謝！

Hi Futari,

Good job!
I presume that you have a successive lecture for "as", don't you? The original question is about whether "as" can substitute "when" or "while" in the two given sentences and in other cases. Thanks.

By the way,
>> The train has just started when we arrived at the station.
I think "has" should be replaced by "had".

Quote:

Right! It's a typo and I had it amended already. Thanks!

Q1. [When he came, I was writing a letter.]
=> As I was writing a letter, he came.
=> He came (just) as I was writing a letter.

Q2. ["While" I was talking to you, you must be quiet.]
=> (if "as" is used) --> "As" I was talking to you, you must be quiet.
(Here, "as" carries the meaning of "because/since", not "at the same moment", "when" or "while" anymore.)

Please correct me if I'm wrong.

Quote:


Haha! No more "lectures" from "Professor" Futari this time. I presume the fifth item under [when] speaks it all.

(You are right! There are at least ten pages on the usage of "as"! Guess no one will bother to read them.)