方法状语从句一般由as, (just) asso, as if, as though引导。
1) as, (just) asso引导的方法状语从句一般坐落于主句后，但在(just) asso结构中坐落于句首，这个时候as从句带有比喻的意思，意思是正如，就像，多用于正式文体，比如：
Always do to the others as you would be done by.
你期望人家如何待你，你就要如何待人。
As water is to fish, so air is to man.
大家不能离开空气，犹如鱼儿不能离开水。
Just as we sweep our rooms, so we should sweep backward ideas from our minds.
正如打扫房子一样，大家也要扫除大家头脑中落后的东西。
2) as if, as though
两者的意义和使用方法相同，引出的状语从句谓语多用虚拟语气，表示与事实相反，有时也用陈述语气，表示所说状况是事实或达成的可能性较大。汉译常作仿佛似的，仿佛似的，比如：
They completely ignore these facts as if (as though) they never existed.
他们完全忽视了这类事实，就仿佛它没有似的。(与事实相反，谓语用虚拟语气。)
He looks as if (as though) he had been hit by lighting.
他那样子就像被雷击了似的。(与事实相反，谓语用虚拟语气。)
It looks as if the weather may pick up very soon.
看来天气非常快就会好起来。(达成的可能性较大，谓语用陈述语气。)
说明：as if / as though也可以引导一个分词短语、不定式短语或无动词短语，比如：
He stared at me as if seeing me for first time.
他目不转睛地看着我，就像首次看见我似的。
He cleared his throat as if to say something.
他清了清嗓子，像要怎么说似的。
The waves dashed on the rocks as if in anger.
波涛冲击着岩石，仿佛非常愤怒。
