一般说来省略现象多出现在下列五种状语从句中:1)由 when ,while ,as ,before, after , till, until, once等引导的时间状语从句;2)由whether ,if , unless 等引导的条件状语从句;3)由though , although ,even if ,whatever等引导的让步状语从句;4)由 as ,than 等引导的比较状语从句;5)由as, as if , as though 等引导的方式状语从句。上述状语从句在省略时应遵循下面原则:
1) 当状语从句的主语与主句的主语一致时,可以省略状语从句的主语和系动词be,这时从句中可出现如下结构:(1) 连词(as, as if , once)+ 名词; (2) 连词( though, whether , when)+形容词;(3) 连词(whether, as if ,while )+介词短语;(4) 连词(when , while , though )+ 现在分词; (5) 连词(when ,if ,even if ,unless ,once ,until, than , as ) + 过去分词; (6) 连词(as if ,as though ) + 不定式。如:
a) Once (he was)a worker ,Pang Long now becomes a famous singer .庞龙曾经是个工人,现在变成一位著名的歌手。
b) Work hard when (you are) young ,or you'll regret.趁年轻要努力学习,要不然你会后悔的。
c) He looked everywhere as if (he was)in search of something .他到处看似乎在找什么东西。
d) While (he was) holding talks with President Hu Jintao ,US President George W. Bush thanked China for its important role in the Six-Party Talks.美国总统布什在与胡锦涛主席会谈时,感谢中国在六方会谈中起的重要作用。
e) The exhibition is more interesting than (it was) expected .这次展览比被预料的有趣的多。
f) Olympic gold medallist hurdler Liu Xiang opened his lips as if (he were) to speak。奥林匹克金牌获得者跨栏运动员刘翔张开嘴好像要说什么。
1) 当从句的主语和主句的宾语一致时,间或也有这样的省略,如:
Her father told her to be careful when (she was)crossing the street.当她过马路时父亲告诉她要当心。
2) 当从句的主语是 it,谓语动词中又含有系动词be 时,可以把it和系动词be一起省略。此时构成连词(if , unless ,when , whenever)+形容词的结构。如:
Unless (it is) necessary ,you'd better not refer to the dictionary.如果没有必要,你最好不要查字典。