Chapter 4 状语从句
4.6 条件状语从句
4.6 条件状语从句
本节主要分析真实条件句，而非真实条件句将在第七章“虚拟语气”中讨论。本节内容安排如下：
4.6.1 常见连词的用法
4.6.2 其他条件状语从句的连词
4.6.1 常见连词的用法
最常见的条件状语从句的引导词是if和unless。连词if表示“如果”，unless表示“如果不”或“除非”。请看例句：
下面这句话读者一定不陌生：
1 If winter comes, can spring be far behind? 冬天来了，春天还会远吗？
有人说爱一个人完全是自己的事情，与对方无关。但不求回报地去爱，又有几人能做到？下面这个例句讲的就是这个道理：
2 Giving someone all your love is never an assurance that they’ll love you back. Don’t expect love in return, just wait for it to grow in their heart, but if it doesn’t, be glad it grew in yours. 为某人付出自己全部的爱，并不一定能够保证对方会同样爱你。不要期望爱的回报，就让爱在对方心中慢慢地成长。即使没有，也不要失望，而要为自己心中曾经爱过而感到高兴。
如果有一天你不经意间微笑起来，连你自己都无法解释为什么自己会笑，那原因就是：
3 Today if a happy smile comes to you, a happy smile that perhaps you can’t explain…it is because at that moment, I am thinking of you, and smiling, too. 假如今天你不经意间开心地微笑起来，连你都无法解释自己为什么会笑……这是因为此时此刻我正在想着你，我也在微笑。
下面这句话是英国前首相撒切尔夫人（Margaret Thatcher）对男人和女人的评价：
4 In politics, if you want someone to make a speech, ask a man; if you want something done, ask a woman. 在政治领域，如果你想要有人发表演说，那就找男士去；而如果你想真正解决事情，那就找女士。
我们再来看有关unless的例句。比如下面这则雅虎发表的免责申明：
5 The opinions expressed here are not necessarily the opinions of Yahoo! And we assume no responsibility for such content…Please do not post any private information unless you want it to be available publicly and never assume that you are completely anonymous and cannot be identified by your comments. 网友在本网站发表的任何评论并不代表雅虎的观点，因而我们对这些内容不承担任何责任。……请不要发布任何个人信息，除非你希望把个人信息公布于众；也不要认为在网络上你是完全匿名隐身的，别人不会因为你的评论而发现你。
一位美国老师指出，中国学生因为“面子”问题而不愿在口语课上开口说英语，下面是他建议其他外教该如何处理中国学生“面子”问题的做法：
6 Discussions about“face”can be difficult if one is not familiar with the significance and importance attached to it by many Asian people. It does have different meanings to different people and, unless a teacher is“comfortable”with broaching the subject, it is best left alone. 亚洲人非常看重“面子”问题，如果你对此不熟悉的话，讨论“面子”问题就会很困难。对于不同的人，“面子”问题的意思是不同的，除非作为老师，你很善于把握这个话题，否则还是不要涉及为好。
下面两个例句都是关于英语学习方面的问题：
7 Read silently. Do not make a sound, move your tongue or lips. Reading aloud slows you down and will not help pronunciation unless you have a mentor who will correct your pronunciation. 默读。读英语的时候，不要出声、动舌头或者动嘴唇。大声朗读会降低你的阅读速度，而且并不有助于你正确地发音，除非你身边有老师能随时帮助你纠正发音。
8 Inside this book you will find a series of successful skills, strategies and suggestions for improving your English, but these will be useless unless you carry them out. 在本书里，你会看到一系列关于如何提高英语水平的成功技巧、方法和建议，不过你要真正运用和实践这些方法，否则它们对你依然毫无用处。
4.6.2 其他条件状语从句的连词
其他引导条件状语从句的连词有：suppose (that)，supposing (that)，providing/provided (that)，so long as，as long as和on condition that等。
读者应该很熟悉下面这句中文谚语：
1 So long as you work hard enough, an iron rod can be ground into a needle. 只要功夫深，铁杵磨成针。
关于年龄与心态的问题，下面这句话值得读者诵记：
2 A man is not old as long as he is seeking something. A man is not old until regrets take the place of dreams.
妙语点睛 这里是as long as表示条件，引导从句。
有人把人生比作自助餐厅，在这里，只要你愿意付出代价和努力，就什么都能得到，但关键是你必须主动、积极，为自己创造一切，你要为自己服务，而不是等着别人来为你服务：
3 Life’s a cafeteria here. You can get anything you want as long as you are willing to pay the price. You can even get success, but you’ll never get it if you wait for someone to bring it to you. You have to get up and get it yourself.人生就是一个自助餐厅，只要愿意付出代价，你就什么都能得到。在这里，你甚至可以获得成功，但如果你只是等待别人来为你服务，你就什么也得不到。你必须行动起来，自己赢得成功。
下面这个例句谈论的是人生目标方向的重要性：
4 Knowledge helps you to reach the destination provided you know what the destination is. 如果你知道自己的目标是什么，知识就能帮助你达到这个目标。
思维训练4.6 Key
请选择最佳答案填空。
1. You can arrive in Beijing earlier for the meeting ______ you don’t mind taking the night train.
A. provided
B. unless
C. though
D. until
2. He will surely finish the job on time ______ he’s left to do it in his own way.
A. in that
B. in case
C. as far as
D. so long as
3. ______ you fell in love with your boss, what would you do?
A. Provide
B. Supposing
C. Unless
D. Except
4. Government cannot operate effectively ______ it is free from such interference.
A. so long as
B. if only
C. unless
D. lest