表示将来时间时，从句用一般现在时
i’ll speak to him when he arrives. (when he will arrive*)
我跟他说当他到达。
when i fall in love, it’ll be forever, or i’ll never fall in love. when i give my heart, it’ll be complete, or i’ll never give my heart.
当我坠入爱河,它会永远,或我永远不会坠入爱河。当我给我的心,它会完成,否则我永远不会给我的心。
*表“将来”的情态动词往往是用于基于一定条件的推测，而不用于表示作为前提的时间或条件等。
when: 某一时刻
i’ll speak to him when he arrives.
i’ll tell him about it when he comes back.
when i arrived, he was talking on the phone.
when i got there, he had already left.
有时也可接延续动词，如：
the doorbell rang when i was telephoning.
*when有时不作“当……时候”讲，而是相当于“……，这时”，这是需要特别注意的用法。
a detective arrested a criminal and was about to handcuff him when a huge gust of wind blew the detective’s hat off.
考题
i was walking along the road ____ suddenly someone patted me on the shoulder from behind. (cet-4)
a.immediately
b.when*
c.the moment
d.while
whenever: 无论何时
whenever you say “i love you”, mean it. whenever you say “i’m sorry”, look the person right in the eyes.
smile whenever you pick up the phone, for the caller will be able to notice it.
while: 相当于during that time, 表示一个时间段，故一般只接延续动词。
the phone rang while i was taking my bath.
the doorbell rang while we were watching tv.
a detective arrested a criminal and was about to handcuff him when a huge gust of wind blew the detective’s hat off.
“shall i go and fetch it?” the criminal asked. “do you take me for a fool?” asked the detective. “you wait here while i go and get it!” (go and fetch整体上构成时间段)
*由“同时”而引申，while表示的另一个重要的关系是“对比”。
until
单独使用：主句谓语动词为延续性动词，表示“到……为止”。
wait until he comes back.
等他回来
we’ll stay here till it stops raining.
我在那等，直到雨停了。
until i came back, he was waiting for me at my home.
not…until: 主句谓语动词为短暂动词，意为“直到……才”。
i didn’t realize how special my mother was until i became an adult.
我没有意识到我母亲是多么的与众不同,直到我成为一个成年人。
one will never realize how much and how little he knows until he starts talking.
一个永远不会实现程度和小他知道直到他开始说话。
ice cream did not reach america until about the middle of the eighteenth century.
冰淇淋没有达到美国直到十八世纪中叶。
i didn’t go to bed until 12 o’clock last night.
我没有上床睡觉,直到昨晚12点。
he didn’t leave the office until his boss came back.
他没有离开办公室,直到他的老板回来。
not until: 主句倒装
not until he saw his mother did the little boy smile
直到他看见他的母亲做了小男孩的微笑
it was not until he saw his mother that the little boy smiled. (为上句的强调结构)
一……就……
as soon as, the minute/the moment/the instant, immediately, directly, instantly:
it began to rain as soon as/immediately/the moment i arrived home.
天就下起雨来了/立即/我一到家。
hardly/scarcely…when, no sooner…than
no sooner had i arrived home than it began to rain.
hardly/scarcely had i arrived home when it began to rain.
no sooner had we begun having dinner than the doorbell rang.