高考二十组易混连（接）词例析 一、表示原因的连词forbecauseassince 【例1】He found it increasingly difficult to read，_his eyesight was beginning to fail Aand BforCbut Dor 【例2】Jenny was very sad over the loss of the photos she had shot at Canada，_this was a memory she especially treasured Aas Bif Cwhen Dwhere 【例3】 Parents should take seriously their childrens requests for sunglasses_eye protection is necessary in sunny weather Abecause Bthough Cunless Dif 【例4】_everybody knows about it，I dont want to talk any more AFor BEven CSince DHowever 【答案与解析】BAAC。引导原因状语从句，asbecausesincefor的区别是：because语势最强，用来说明人所未知的原因，回答why提出的问题，可置于强调句中且其前可加修饰语；since是双方都知晓原因或经过分析而得之的原因，语气次之；for是并列连词，前用逗号隔开，表逻辑推理或补充说明；as语气最弱，原因是显而易见的或已为人们所知，即已知原因，所引导的分句可置于句首。 二、特殊并列连词whilewhen 【例5】I had just stepped out of the bathroom and was busily drying myself with a towel_ I heard the steps Awhile Bwhen Csince Dafter 【例6】Id like to study law at universitymy_ cousin prefers geography Athough Bas Cwhile Dfor 【答案与解析】BC。作并列连词时，whenwhile用法较为特殊，二者区别是：while表两相对照;而when表突然、在那时，常见于be about to dowhen和Hardlywhen等句型中。 三、并列连词butyetthough 【例7】Excuse me for breaking in，_I have some news for you Aso Band Cbut Dyet 【答案与解析】C。but和yet是连词，可等同使用，但也有区别。yet与and连用，构成and yet，但but却无此用法；在“Excuse meIm sorryI hope you dont mindbut中，只用but，不用yet。因为在表示对照或对立时，but较为轻松自然；而yet却较为强烈，常出人意料;though作并列连词时，只能引导分句且其前须加逗号。例： Ill try to come，though I dont think I shall manage it 四、引导名词性从句的从属连词thatwhetherif 【例8】The traditional view is_we sleep because our brain is “programmed” to make us do so AwhenBwhyCwhetherDthat 【例9】We havent settled the question of_ it is necessary for him to study abroad Aif BwhereCwhetherDthat 【答案与解析】DC。引导名词性从句的从属连词that与whether的区别是：句子成分完整且表意确定时选用that连接，句意不确定时选用whetherif连接;借助it,将真正主语或宾语后置，构成“Itthat”句型，但whetherif不可；下列情形用whether不用if:与or not连用，中间无其他词隔开；作介词宾语；在主语从句、表语从句和同位语从句中。例 Whetherwell go camping tomorrow depends on the weather 五、表示比较的从属连词whatas 【例10】Engines are to machines_hearts are to animals Aas Bthat Cwhat Dwhich 【例11】_I explained on the phone，your request will be considered at the next meeting AWhen BAfter CAs DSince 【例12】What a table! Ive never seen such a thing beforeIt is_it is long Ahalf not as wide asBwide not as half as C. not half as wide asDas wide as not half 【答案与解析】CCC。what用作从属连词，表比较，用于A is to B what C is to D结构中；而as表示原级比较，常用于asas结构中，程度修饰语应置于第一个as之前，嵌入的形容词或副词使用原级。另外还表“正如、按照”，引导方式状语从句。 六、表示条件的从属连词ifunlessas long asonce 【例13】_I know the money is safe，I shall not worry about it. AEven though BUnless CAs long as DWhile 【例14】Small sailboats can easily turn over in the water_they are not managed carefully Athough Bbefore Cuntil D. if 【例15】You will be successful in the interview_you have confidence Abefore Bonce Cuntil Dthough 【例16】I wont call you，_something unexpected happens Aunless Bwhether Cbecause Dwhile 【答案与解析】CDBA。表条件的连词ifunlessas long asonce在用法上存在一些差异。as long as用法同only ifon condition that，强调某事的发生以另一事件的发生为前提；if为正面条件，可能会产生好的或坏的结果，若某种条件产生坏的结果，此时的if可用as long as替换；unless为反面条件，表示除非，如果不，故在真实条件句中常和ifnot换用；once既表时间，又包含条件，译作一旦。 七、表示让步的从属连词althoughwhenwhile 【例17】We had to wait half an hour _ we had already booked a table AsinceBalthough C. until Dbefore 【例18】_I really dont like art,I find his work impressive AAs BSince CIf DWhile 【答案与解析】BD。althoughwhenwhile均可表示让步，后两者的用法较为特殊。althoughthough引导让步状语从句时不与but和yet连用;而while却表示“部分接受，但并非全部”，或用于“强调两种情况、活动等之间的差距”;when也可表示虽然，尽管，同even if,常置于句末。例： (1)While I accept that he is not perfect,I do actually like the person (2)He walks when he might take a taxi if用作从属连词，也可表让步，类似though，用以描述自己喜爱的人或物。如：Hes a pleasant child，if a little spoiled 八、从属连词so thatin case 【例19】Id like to arrive 20 minutes early_I can have time for a cup of tea Aas soon as Bas a result Cin case Dso that 【例20】Leave your key with a neighbor_you lock yourself out one day Aever since Beven if Csooner after Din case 【答案与解析】DD。so that既表示结果又表示目的。若置于主句后，用逗号隔开常表结果；与情态动词连用常表目的。in case表示假设，译作“万一”。例： I always take something to read when I go to the doctors in case I have to wait 九、关联连词sosuchthat 【例21】Pop music is such an important part of society_it has even influenced our language Aas BthatCwhich Dwhere 【例22】_homework did we have to do that we had no time to take a rest ASo much BToo much CToo little DSo little 【答案与解析】BA。关联连词sosuchthat(如此以致)，只表结果，置于句首时，主句要部分倒装;so为副词，后续形容词或副词。such后续名词，名词前可接限定词；such that可表程度。例：Her cruelty is such that we all hate her 十、表原因的从属连词now thatin that 【例23】_