if用法详解(三) if的省略&倒装

if用法详解(三) if的省略&倒装

if-型省略结构及省略if而引起的倒装现象在中学英语教材中经常出现，而且也是高考一个十分重要的考点，本文拟对其可能涉及的结构作一全面归纳。

I省略if倒装

当虚拟语气在非真实条件句使用时，if可以省略，从而引起倒装，即把were，had，should提前，以强调假设条件的虚拟性或突出说话人的主观愿望。

(1)表示与现在事实相反的情况

If  I were you, I would never take Shelly somewhere dangerous.

Were I you, I would never take Shelly somewhere dangerous.

如果我是你，我永远不会带雪莉去这么危险的地方。

(2)表示与过去事实相反的情况

If Shelly had worked out 23 hours a day, she wouldn't have got constipated.

Had Shelly worked out 23 hours a day, she wouldn't have got constipated.

如果雪莉之前每天锻炼23个小时，她就不会便秘了。

(3)表示与将来事实相反 

If Shelly were to stay on Salmon Planet, cheaper treatment couldn't be worked out.

Were Shelly to stay on Salmon Planet, cheaper treatment couldn't be worked out.

如果雪莉要待在鲑鱼星球，她就找不到便宜的治疗方法。

II if从句中的省略 

(1)if + 形容词

这类结构通常可视为在if与形容词之间省略了主语+动词be。

Send the goods now if (they are ready).

货物如已备好，请即送来。

If (it is) true, this will cause us a lot of trouble.

这事若是事实，它将给我们造成许多麻烦。

If necessary, ring me at home. 

如果必要，可往我家里打电话。

If possible, let me know beforehand. 

如果可能，可在事前通知我。

If (it is) convenient, do come to attend our party in Hilton Restaurant tomorrow．

如果方便的话，明天一定要来参加我们在希尔顿饭店的聚会。

(2)if + 过去分词

其中过去分词可视为是被省略的被动结构，即在if与形容词之间省略了主语+动词be

He will come if (he is) asked.

他受邀就会来。

The medicine is quite effective if (it is) taken in time.

这药要是能按时服用，效果是很好的。

(3)if + 代词

这类省略通常要根据具体的上下文来理解。

①if (there is) anything

a.如有什么不同的话（之前多已提及相反的情况）;

I haven't made much of this—if anything, I've played it down.

对此我并没有加以重视——要说有什么区别的话，那我是看淡它了。

b.若要说的话；

He seems to have little, if anything, to do with this. 

若要说他和这事有什么相关的话，那也似乎是很少的。

c.甚至正相反

He is not diligent,if anything, he is clever.

他不勤奋，正相反，他很聪明。

②if any表示数量：如果有(一些)

There are few people nowadays, if (there are)any (people), who remember him. 

当今记得他的人，如有的话，也不多了。

(4)if + 介词短语

这类结构往往要根据具体的语境来理解。

①if in doubt如果有疑问

If(you are) in doubt, ask your doctor. He can give you further information. 

你若有疑问，可以问问医生. 他会向你作进一步的说明。

②if at all即使...也；要是...就

Their policies have changed little, if at all, since the last election. 

自上次选举以来，他们的政策就算是有变化，也变得很少。

Drink in moderation, if at all.

要是喝酒，就适量喝。

③if at all possible尽可能

Work at home if at all possible.=Work at home if it is possible at all.

如果可能的话，尽量在家办公。

④if by any chance万一

If by any chance you can’t manage dinner tonight, perhaps we can at least have a drink together. 

就算你今晚不吃晚饭，也许我们至少可以一起喝一杯。

注：以上if省略结构中，省略的主语可以是there、it、以及与从句一致的主语；如主从句主语不一致或从句中缺乏be动词，则不能省略。

If an eyewitness to the accident is brought in, you are sure to be proved innocent.

如果有一个目击事故的证人在场，你肯定会被证明是无辜的。

If the host invites the superstar, he would be glad to show up at the celebration.

如果主持人邀请那位超级巨星，他会很高兴出席庆祝活动的。

(5)if ever

if ever 可视为习语，它通常与seldom连用，具有否定意味，表示“极少”“难得”，“几乎”“即使...也”

She seldom, if ever, goes to the cinema. 

她难得看电影。

He seldom if ever travels abroad. 

他到国外旅行，即使有过，也是极少的。

The island is seldom if ever visited by ships. 

这个岛难得有船停靠。

If ever you’re in Cambridge, do give me a ring. 

万一你来剑桥，一定要给我打电话。

(6)if not

if not 可视为一个否定的条件状语从句省略,“如果不是(那样)的话”

I might see you tomorrow. If not, then it’ll be Saturday. 

我可能明天去看你。如果不是明天，那就在周六。

Ask her if it is a convenient time. If not, can she suggest another possible time? 

问问她那个时间方便不方便。要是不方便，那她可不可以提出一个可行的时间?

If not today, tomorrow I’m sure you’ll get an answer. 

如果今天得不到回信，明天准能得到。

if not 还可后接表示对等比较的省略成分：

This is one of the oldest buildings in town, if not the oldest. 

这是城里最古老的房屋之一，如果不是最古老的话。

Usually, if not always, we write “cannot” as one word. 

我们即使不总是如此，也通常是把cannot作为一个词来拼写的。

That alligator would be every bit of 11 foot, if not a little bit bigger.

那只鳄鱼其实体量不错。就算没有更大，也基本有11英尺了。

Much emphasis is put on how to spend as much time if not more studying by themselves as being taught.

如果没花更多的时间自己学习，人们会把重点放在如何花费尽可能多的去接受教导。

His pronunciation, if not good, is at least tolerable. 

他的发音如果说不算好，也还过得去。

We all know that,  if not carefully dealt with the situation will get worse.

我们都知道，如果不小心处理的话，情况会变得更糟。

Though he started late, Mr. Guo played the piano as well as, if  not better than, Miss Liu.

    虽然他弹钢琴开始得晚，但郭先生如果好不过，也弹得跟刘小姐一样好。

(7)if not more than

表示比较对象在程度上接近或一致：至少也；即使...也

In that business，he earned as much as，if not more than，$40000.

在这个行业，他赚的钱起码有4万美元。

Jim plays football as well as，if not better than，Mike.

吉姆踢足球如果不是比迈克踢得更好，至少也是一样好。

Her pronunciation is as good as，if not better than，her teacher's. 

她的发音和她的老师一样好，甚至更好。

This bridge is as strong as，if not stronger than，that one. 

这座桥即使没有比那座更坚固，也一样坚固。

He has been to Guilin as many as，if not more than，ten times.

他去过桂林不下十次。

(8)if so

与if not意思相反：如果(情况是)那样的话

I may be free this evening. If so, I’ll come round and see you. 

今晚我可能有空。要是有空我会过来看你。

They must decide if such a plan can be implemented and if so, when. 

他必须决定这样的计划是否能实施，而且要是能实施的话，又得决定何时实施。

He may be busy. If so, I’ll call later. If not, can I see him now? 

他可能忙，这样的话，我以后再来拜访。他如不忙，我现在可以见他吗?

Will you be staying another night? If so, we can give you a better room. If not, could you be out of your room by 12:00? 

您要再往一晚吗? 如果是这样，我们可以给您提供条件更好一点的房间。如果不是， 您能在12点前离开这房间吗?

(9)if need be 

if need be为习语，其含义相当于if (it is) necessary如果有必要的话：

I will come if need be. 

如有必要我会来。

I’ll work at night if need be. 

如果有必要我可以晚上工作。

If need be we can always bring another car. 

如果有必要的话我们还可以再开一辆车来。

Disputes are rare and would, if need be, have to be resolved in the courts.

纠纷很少发生，如果有必要，必须通过法庭解决。

(10)if and only if

强调充分必要条件: 当且仅当

Witches are real if and only if there are criteria for identifying witches.

当且仅当有标准识别女巫，女巫才是真实存在的。

(11)if and when

固定惯用语,可以看作是一个单位:如果，万一

If and when the film gets the green light, be sure you've read the book first.

万一电影得到许可，千万保证你已经读过那本书了。

If and when we ever meet again I hope he remembers what I did for him.

如果我们再见面，我希望他记得我为他做了什么。

(12)if I were you

提出建议或劝告: 换作是我

I would go to see him if I were you./ Were I you, I would go to see him.

换作是我，我会去见他。

(13)if only

①if only + to do sth.略含让步语气：即使只为了

Willy would have to tell George more, if only to stop him pestering.

即使只为了阻止乔治惹恼别人，威利也会告诉他更多的。

②if only+ 条件从句 表达对于现在、过去或将来的遗憾、愿望或不满：要是…就好了

If only I were as clever as you!(You’ve solved all the riddles.)

我要是能像你一样聪明该多好啊！

If only I had listened to you.(It’s too late now.)

如果我听你了的话就好了。

If only he would call.

只要他打来电话就好！

比较：only if增强主句语势：只有...才

I could buy the house only if a mortgage for 2000 dollars is available.

只有拿到2000美元的抵押贷款，我才能买得起那个房子。

Only if presented in this way can your idea get over to the audience.

只有用这样的方式提出来，你的意思才能让听众明白。

(14)no ifs or buts

别找借口；别讨价还价；没得商量

There’s no ifs or buts you have to be finished on a date.

没有任何借口可言，在规定的日子，你必须完成工作。

no ifs or buts---- just do as I tell you!

没有任何理由跟借口，照我说的去做！

    (15)make as if to do something

假装做某事；似乎要

I didn’t get up, but only because you made as if to answer the door.

我没有站起来，只是因为你假装要开门。

Mary made as if to protest, then hesitated.

玛丽似乎要抗议，又犹豫了。

He made as it to resume their embrace, but Polly raised a hand to stop him.

他想重新拥抱他们，但波莉举起一只手阻止了他。