【状语从句用法例析】时间状语从句例句10句
一、状语和状语从句的定义 （一）状语 状语修饰动词、形容词、副词或整个句子。通常由副词、介词短语、动词不定式、分词和从句等担当。例如：
Naturally, our grandparents were pleased to get our phone call. (副词)
We worked hard, from sunrise to sunset. (介词短语)
To help my disabled aunt, I spend an hour working in her house every day. (不定式)
Seen from a distance, the farmhouse looked deserted. (过去分词)
I know how to light a camp fire because I had done it before.（原因状语从句）
状语的位置比较灵活，可以位于句首、句末或句中。enough用作状语修饰形容词和副词时必须后置。
（二）状语从句
状语从句是状语的特殊形式，根据含义可分为时间、地点、原因、目的、结果、条件、行为方式、比较、让步等9种。状语从句通常由一个连词或起连词作用的词组引起。例如：
Don’t be afraid of asking for help when it is needed.
状语从句一般有两种排列顺序：
A ) 主句+连词+状语从句
B ) 连词+状语从句，主句
二、状语从句的简化
（一）状语从句的省略
状语从句同时具备下列两个条件:一是主句和从句的主语一致，或从句主语为it，二是从句主要动词是be的某种形式，从句中的主语和be动词常可省略。例如：
When (the museum is) completed, the museum will be open to the public next year.
另外，比较状语从句经常省略。例如：
I’m taller than he (is tall ).
（二）状语从句和状语的转换
■状语从句主句和从句主语一致时，转换为分词短语。
When the city is seen from the mountain, it looks much more beautiful.
Seen from the mountain, it looks much more beautiful.
■状语从句主句和从句主语不一致，转换为独立主格结构。
If weather permits, we’ll have the meeting in the open air.
(With) Weather permitting, we’ll have the meeting in the open air.
■状语从句转换为介词短语。
由after/before/since/as soon as等引导的时间状语从句，可改为“after/before/since/on+动名词短语”结构。当主从句主语不一致时，可使用动名词的复合结构。
Before he dived into the lake, he made a deep breath.
Before diving into the lake, he made a deep breath.
■状语从句转换为动词不定式短语。
He is so strong that he can lift the heavy stone.
He is strong enough to lift the heavy stone.
三、状语从句的动词时态和语气
状语从句主句和从句的时态要保持一致。注意下列情况：
1.在时间状语从句和条件状语从句中，主句是一般将来时/祈使句/含有情态动词原形，从句要使用一般现在时态。但will在表示意愿时，可用于上述状语从句。
2.在so that (in order that)引导的目的状语从句中，谓语动词用“can(could)/may(might)/will(would)/should＋动词原形”的形式。so that引导结果状语从句时，不用此要求限制。
3. as if (though)引导方式状语从句，陈述情况可能性小，谓语动词用虚拟语气，即时态在原基础上向过去退一步。若从句所述情况可能实现，则用陈述语气。
4.no sooner...than.../hardly (scarcely)...when...表示“-……，就……”，引导时间状语从句，主句须用过去完成时，从句用一般过去时。no sooner/hardly (scarcely)位于句首，主句倒装。
5.if引导非真实条件状语从句要使用虚拟语气。
If I had enough money, I should (would) buy the car. （事实上现在钱不够）
If I had got up earlier I should (would) have met her. （事实上那时我起床晚了）
If he would come here tomorrow, I should (would) talk to him.（事实上明天来的可能性极小）
四、状语从句常见引导词 各类状语从句的引导词是高考命题热点。
1.时间状语从句
关联词：as/when/while，after，before， since， till/until no sooner...than/hardly... when
副词：immediately，directly
名词短语：the moment， the minute， the second， each (every)time，the day (year)， next time， the first (second/last) time， by the time
2.条件状语从句
if，unless， as(so) long as， on condition that， suppose (supposed) that， provide(providing) that， in the event that
3.原因状语从句
because， as， since， now (that)
4.结果状语从句
so (such )...that...
5.目的状语从句
so that， in order that，in case
6.让步状语从句
though， although，as， however， no matter...，疑问词+ever，whether...or not
7.比较状语从句
than， as(so )...as， the more...the more
8.方式状语从句
as， as if， as though
9.地点状语从句
where， wherever
（作者单位：河南省登封市嵩阳高级中学）