专题八 状语从句、定语从句状语从句一、时间状语从句1．before 引导的从句中不用否定式谓语。常用如下句型：It is long before...(过了好久才……)It is not long before...(过了不久就……)2．since 后面所用动词不同，该动词所表示动作持续时间的计算方法也不同。It is two years since he joined the army.It is two years since he smoked.二、地点状语从句多由 where 和 wherever 引导。Where there is a will，there is a way.二、原因状语从句在表示原因时，because 语气最重，其次是 as，since，now that，故在回答 why 问句或者在强调句对原因进行强调时，只能用 because。for 是并列连词，表示推测的理由或者进一步说明，不能放在句首，for 前要用逗号。—Why were you absent?—Because I was ill.三、目的状语从句1 ． so that/in order that 引 导 的 目 的 状 语 从 句 中 的 谓 语 动 词 多用 can/could/may/might/will/would＋动词。Please turn off the light so that I can go to sleep.2．for fear that，in case，lest 表示“以防，免得”。He is working hard for fear that he should fail.四、条件状语从句1．providing/provided (that)假如，假若Providing (that) no one has further questions，the meeting will be over.2．on the understanding that＝on condition that 在……条件下I give you money on the understanding that you finish your homework.五、结果状语从句注意 such 引导的结果状语从句与定语从句的区别。试比较：This is such an interesting book that everyone likes to read it.This is such an interesting book as everyone likes to read.六、目的状语从句与结果状语从句的区别in order that 可放在句首，只能引导目的状语从句；so that 引导目的或结果状语从句，不能放在句首。试比较：He spoke so slowly that we all followed him.( 结 果 状 语 从 句 ) ＝ He spoke slowly，so we all followed him.He spoke slowly so (in order) that we could all understand him.(目的状语从句)七、让步状语从句1．as 引导让步状语从句，作“尽管”解，用倒装句，语序为：状语/宾语/表语/动词原形＋a...
