時間狀語從句主要由以下連詞引導(dǎo)：when, whenever, as, while, since, until, till, before, after, as soon as, once, hardly (scarcely) … when, no sooner … than。
I will discuss the matter with you when we meet tomorrow.
He didn’t go to sleep until he finished doing his homework. You have changed a lot since we met last time.
時間狀語從句還可由某些可充當(dāng)連詞的名詞(the moment, the instant, every time,等)和副詞(instantly, directly等)引導(dǎo)：
I will tell you the news the instant I know.
Directly the teacher came in everyone was quiet.
Note:
① before除了可表示 “在…之前”外，還可用來強(qiáng)調(diào)主句所表達(dá)的時間、距離很長或花費(fèi)的力量相比較大，可譯為“…才”。(“not … before” 可用來強(qiáng)調(diào)主句所表達(dá)的時間、距離很短或花費(fèi)的力量相比較小，可譯為“…就”)。
It was a long time before I got to sleep again.
They had not been married a month before they quarreled.
② 如果位于when引導(dǎo)的分句之前的主句使用過去進(jìn)行時、過去完成時或“was/were about to, was/were on the point of”等結(jié)構(gòu)時，when表示突然發(fā)生某事，可譯為“正在…突然”或“剛…就”等。這時，不能夠用as或while來代替when。
I was walking on the street when I ran into my old friend John.
She had just fallen asleep when the telephone rang.
We were about to leave when it began to rain.
I will discuss the matter with you when we meet tomorrow.
He didn’t go to sleep until he finished doing his homework. You have changed a lot since we met last time.
時間狀語從句還可由某些可充當(dāng)連詞的名詞(the moment, the instant, every time,等)和副詞(instantly, directly等)引導(dǎo)：
I will tell you the news the instant I know.
Directly the teacher came in everyone was quiet.
Note:
① before除了可表示 “在…之前”外，還可用來強(qiáng)調(diào)主句所表達(dá)的時間、距離很長或花費(fèi)的力量相比較大，可譯為“…才”。(“not … before” 可用來強(qiáng)調(diào)主句所表達(dá)的時間、距離很短或花費(fèi)的力量相比較小，可譯為“…就”)。
It was a long time before I got to sleep again.
They had not been married a month before they quarreled.
② 如果位于when引導(dǎo)的分句之前的主句使用過去進(jìn)行時、過去完成時或“was/were about to, was/were on the point of”等結(jié)構(gòu)時，when表示突然發(fā)生某事，可譯為“正在…突然”或“剛…就”等。這時，不能夠用as或while來代替when。
I was walking on the street when I ran into my old friend John.
She had just fallen asleep when the telephone rang.
We were about to leave when it began to rain.