职称英语等级考试各重点语法考点解析2

　　职称英语等级考试各重点语法考点解析2

　　1、注意状语从句中从句的省略现象

　　连接词 + 过去分词

　　Dont speak until spoken to.

　　Pressure can be incrased when needed.

　　Unless repaired, the washing machine is no use.

　　连词 + 现在分词

　　Look out while crossing the street.

　　连词 + 形容词/其他

　　常见的有it necessary、if possible、when necessary、if any等

　　2、让步状语从句

　　although与though可以引导让步状语从句,不能与but连用,但可以与yet连用.

　　Although they are poor,they are warm-hearted.

　　even if或even though引导让步状语从句,表示即使,纵然,用来使人注意下文所强调内容的性质.

　　Ill get there even ifI have to sell my house to get enough money to go by air.

　　no matter后接上who、what、where、how等疑问词,也可以在这类疑问词后面加上ever构成whoever、whatever、wherever、however等.

　　Dont trust him, no matter what / whatever he says.

　　Whoever breaks the law will be published.

　　No matter how hard the work is, youd better try to do it well.

　　as也可以引导让步状语从句.要用倒装.

　　Child ashe is, he knows a lot.

　　Much as I like it, I wont buy.

　　Try as he would, he couldnt lift the heavy box.

　　3、原因状语从句:because, for, as, since, now that

　　表示不知道的原因时用because,即说话人认为听话人不知道,因此because从句是全句最重要的部分,通常它被置于主句之后.

　　You want to know why Im leaving? Im leaving because Im full.

　　for虽然表示不知道的原因,但其语气较because要弱得多,是可说可不说的话,它只能置于主句之后,这时,for是并列连词.如果不是因果关系,而是对前面主句的内容加以解释或推断时,只能用for.如:Its morning now, for the birds are singing.

　　表示已经知道的原因时用as或since,即某种原因在说话人看来已经很明显,或已为听话人所熟悉,因此它是句中不很重要的部分.since要比as正式一些,它们通常被置于语句之前,但有时却相反.

　　Seeing all of the children already seated, he said,Since everyone is here, lets start.

　　下列情况下只能使用because:

　　①在回答why的问句时;

　　②在用于强调句型时;

　　③被not所否定时.

　　4、地点状语从句:where, wherever

　　Make a mark wherever you have any questions.

　　We will go where the Party directs us.

　　5、目的状语从句:that, so that, in order that

　　注意:目的状语从句的谓语动词常与情态动词连用,否则可能是结果状语从句.不可置于句首.

　　6、结果状语从句:that, so that, so that, such that

　　注意:so + 形容词/副词 + that从句;such + 名词 + that从句.

　　7、方式状语从句:as, as if

　　Ill do as I am told to.

　　It looks as if it is going to rain.

　　8、比较状语从句:than, as

　　9、条件状语从句:if, unless, so long as, in case, once, a far as, on condition that.

　　注意if与unless的区别:不能用and连接两个unless从句,即不能有 unless ,and unless .

　　但if not and if not却不受此限.

　　You wont lose your weight unless you eat less and unless you exercise more.

　　但可以说 unless you eat less and exercise more.