(1)unless意为“除非”,相当于if not,引导条件状语从句,如果主句是一般将来时态,从句则用一般现在时态。如:
①The sports meeting will continue unless it rains this afternoon.除非下午下雨,不然运动会还将继续。
②He cannot turn himself into a person unless he can hide his tail.他不能把自己变成人,除非他把尾巴藏起来。
2)as soon as意为“一……就……”,相当于when,引导时间状语从句,如果主句是一般将来时态,从句则用一般现在时态。
①As soon as he sees bad people, he thinks of ways to fight them.他一看到坏人,就想办法打他们。
②She will send us a message as soon as she gets to Sydney.她一到悉尼就会给我们发信息
(3)so... that意为“如此……以至于……”, 引导结果状语从句,so后面接形容词或者副词,that后面接句子。如:
①That bird's song is so beautiful that we should follow it.那只鸟的歌曲是如此优美以至于我们应该跟着它。
②Sometimes he makes the stick so small that he can keep it in his ear.有时候他把棍子变得如此的小以至于他能把它放在耳朵里