连词的使用规则
一 含义
连词是一种虚词，用于连接单词、短语、从句或句子，在句子中不单独用作句子成分。
二 分类：并列连词和从属连词
并列连词用于连接并列的单词、短语、从句或句子，如and, but, or, for等。
从属连词主要引出名词性从句（主语从句、宾语从句、表语从句等）和状语从句（时间状语从句、条件状语从句、目的状语从句等），引出名词性从句的连词如that, whether等，引出状语从句的连词如when, because, since, if等（详见后面后部分）。
三 并列连词的用法
1．表示转折关系的并列连词。主要有but（但是）, yet（可是）, while（而，却）等。
注意：根据英语习惯，although/though不能与连词but搭配使用，但是although可以与yet搭配连用（此时的yet可视为副词）。
《剑桥雅思真题8》Test 1 Passage 1
Although these devices performed satisfactorily around the Mediterranean, they could not always be depended on in the cloudy and often freezing weather of northern Europe.
尽管这些设备在地中海周围运行良好，但在北欧多云和经常寒冷的天气中，它们不可能总是可靠的。
《剑桥雅思真题7》Test 2 Passage 1
Yet it left the magnificent five-storey pagoda at the Toji temple in nearby Kyoto unscathed, though it levelled a number of buildings in the neighbourhood.
然而，它在京都附近的Toji寺庙中留下了宏伟的五层塔，没有受到任何伤害，尽管它将附近的一些建筑物被夷为平地。
2．表示选择关系的并列连词：
or（或者，还是，否则）, either…or…（不是……就是……）, neither…or…（既不……也不……）, otherwise（要不然）等。
3．表示因果关系的并列连词。
主要有for（因为）, so（因此）等。
（1）for的“几个不能”。
表示原因通常不能放句首，也不能单独使用；
for引导的从句不能位于它所解释的动词之前；
for引导的从句不能位于not, but或任何连词之后；
for引导的从句不能用于回答问题。
《剑桥雅思真题8》Test 3 Passage 2
We may disagree with the ‘general', for we doubt if all musicians of genius could have become scientists of genius or vice versa.
我们可能不同意“普遍情况”，因为我们怀疑是否所有天才音乐家都能成为天才科学家，反之亦然。
（2）so用作连词，主要用于表结果，意思为“所以”。
有时可与并列连词and连用，构成习语and so（相当so）
《剑桥雅思真题8》Test 3 Passage 3
Thus they are not able to ‘experience life' and so they attain a high life span in captivity.
因此，他们不能“体验生命”，所以他们在囚禁中获得了较高的寿命。
将“因为……所以……”直译为because…so…，但两者不可同时使用。
《剑桥雅思真题8》Test 2 Passage 3
Odours, unlike colours, for instance, cannot be named in many languages because the specific vocabulary simply doesn't exist.
例如，气味不同于颜色，在许多语言中无法命名，因为特定的词汇根本不存在。
4．表示并列关系的连词and。
注意：在主从复合句中，不要在主句前误加and。
《剑桥雅思真题9》Test 3 Passage 2
If tide, wind and wave power are all developed,（and）Britain would be able to close gas, coal and nuclear power plants.
如果潮汐、风能和波浪能都得到开发，英国将能够关闭天然气、煤炭和核电站。
四 从属连词的用法
1．引导时间状语从句的从属连词（详见状语从句部分）。
（1）表示“当……时候”的时间连词。主要的有when, while, as, whenever。
（2）表示“在……之前（或之后）”的时间连词。主要的有before, after。
（3）表示“自从”或“直到”的时间连词。主要的有since, until, till。
2．as用作连词的用法。
（1）表示伴随，意思为“随着”。
《剑桥雅思真题7》Test 3 Passage 1
Only basic instincts are carried in the genes of a newborn baby, other skills being learned from others in the community as the child grows up.
新生儿的基因中只有基本的本能，随着孩子的成长，其他技能也会从社区里的其他人那里学到。
（2）表示让步，意思为“虽然”“尽管”，要用于倒装句（相当于though，但语气稍弱）。
《剑桥雅思真题7》Test 2 Passage 2
In Britain, for example, many of our best-loved farmland birds have vanished from huge stretches of countryside, as have even more wild flowers and insects.
例如，在英国，我们最喜爱的许多农田鸟类已经从大片的乡村消失，还有更多的野花和昆虫。
（3）表示时间，意思为“当……时候”。
《剑桥雅思真题8》Test 4 Section 3
As I revise each topic I write a single paragraph about it.
当我修改每一个主题的时候，我会写一个关于它的段落。
（4）表示原因，引导原因状语从句时（详见状语从句部分）。
3．引导条件状语从句的从属连词，主要的有if, unless, as [so] long as, in case等。（详见状语从句部分）
4．引导目的状语从句的从属连词，主要的有in order that, so that, in case, for fear等。（详见状语从句部分）
5．引导结果状语从句的从属连词，主要的有so that, so…that, such…that等。（详见状语从句部分）
6．引导原因状语从句的从属连词，主要的有because, as, since, seeing (that), now (that), considering (that)等。（详见状语从句部分）
7．引导让步状语从句的从属连词，主要的有although, though, even though, even if, while, however, whatever, whoever, whenever, wherever等。（详见状语从句部分）
8．引导方式状语从句的从属连词，主要的有as, as if, as though, the way等。（详见状语从句部分）
9．引导地点状语从句的从属连词，主要的有where, wherever, everywhere, anywhere等。（详见状语从句部分）
10．引导比较状语从句的从属连词，主要的有than和as…as。（详见状语从句部分）
11．引导名词性从句的从属连词，主要的有that, whether, if等，它们用于引导主语从句、表语从句、宾语从句和同位语从句。其中that不仅不充当句子成分，而且没有词义，在句子中只起连接作用；而if, whether虽不充当句子成分，但有词义，即表示“是否”。（详见名词从句部分）
五 连词总结
1．表递进：moreover, in addition, what is more, furthermore, also, then, besides, what's worse。
《剑桥雅思真题11》Test 2 Passage 2
Moreover, Hunt and Lipo are convinced that the settlers were not wholly responsible for the loss of the island's trees.
此外，Hunt和Lipo相信树木破坏并非完全由岛上居民所致。
《剑桥雅思真题9》Test 3 Passage 1
Language, moreover, is a very public behaviour, so it is easy for different usages to be noted and criticized.
此外，语言是一种非常公开的行为，因此不同的用法很容易被注意和批评。
《剑桥雅思真题7》Test 2 Passage 2
Furthermore, the price premium would put the produce out of reach of many poorer consumers.
此外，价格溢价将使许多较贫穷的消费者买不起这些产品。
2．表转折：however, nevertheless, on the other hand, on the contrary, rather than, instead of, but, yet, whereas。
《剑桥雅思真题9》Test 3 Passage 1
Nevertheless, there is an alternative point of view that is concerned less with standards than with the facts of linguistic usage.
然而，还有一种不同的观点，与其说是关注标准，不如说是关注语言使用的事实。
《剑桥雅思真题2》Test 4 Passage 2
On the contrary, a great deal of empirical evidence shows that pictures interfere in a damaging way with all aspects of learning to read.
相反，大量的经验证据表明，图片以一种破坏性的方式干扰了学习阅读的各个方面。
3．表层次：on the one hand, …on the other hand; first, …second, …finally。
《剑桥雅思真题9》Test 4 Passage 2
On the other hand, they found that children of 15 to 18 months are generally not able to recognize themselves unless other cues such as movement are present.
另一方面，他们发现15到18个月大的孩子通常不能识别自己，除非有其他的线索，比如运动。
4．表强调：in fact, indeed, actually, as a matter of fact, obviously, apparently, of course, interestingly, above all, surely, certainly, undoubtedly, in any case, anyway, especially, obviously, clearly。
《剑桥雅思真题7》Test 4 Passage 3
Apparently, unpredictable noise produces more fatigue than predictable noise.
显然，不可预测的噪音比可预测的噪音产生更多的疲劳。
《剑桥雅思真题7》Test 3 Passage 3
In Europe, it is undoubtedly the mountain ecosystem has changed most rapidly and is most at risk.
在欧洲，无疑是山地生态系统变化最快、风险最大。
《剑桥雅思真题8》Test 4 Passage 3
This method works especially well in rain forests and marshy areas.
这种方法在雨林和沼泽地区尤其有效。
5．表结果：evidently, without any shadow of doubt, as a result, thus, hence, so, therefore, accordingly, consequently, as consequence。
《剑桥雅思真题9》Test 3 Passage 1
As a result, it is easy to hurt, and to be hurt, when language use is unfeelingly attacked.
因此，当无意间发生语言攻击时，人们很容易伤害他人或受到伤害。
《剑桥雅思真题6》Test 3 Passage 2
Accordingly, high achievers should not be put into jobs that are inconsistent with their needs.
因此，不应将高成就者纳入与其需求不一致的工作。
《剑桥雅思真题8》Test 2 Passage 1
Consequently, when pouring molten glass onto the molten tin, the underside of the glass would also be perfectly flat.
因此，当把熔融的玻璃倒到熔融的锡上时，玻璃的底部也会非常平整。
6．表总结：on the whole, in conclusion, in a word, to sum up, in brief, in summary, to conclude, in short。
《剑桥雅思真题4》Test 4 Passage 2
In conclusion, devise a model that seems best to summarise the pattern observed in the data.
综上所述，设计了一个模型来总结数据中观察到的模式。
《剑桥雅思真题8》Test 2 Passage 1
In short, the shinbashira was acting like an enormous stationary pendulum.
简而言之，中心柱就像一个巨大的静止的钟摆。
7．表类比：like, similarly, likewise, in the same way, in the same manner, equally。
《剑桥雅思真题7》Test 1 Passage 3
Likewise, the students are instructed not to try to learn it during this introduction.
同样地，学生们也被告知在介绍的过程中不要试图去学习它。
8．表对比：by contrast, on the contrary, while, whereas, on the other hand, unlike, instead, but, conversely, different from, however, nevertheless, otherwise, unlike, yet, in contrast, by comparison。
《剑桥雅思真题8》Test 2 Passage 3
Odours, unlike colours, for instance, cannot be named in many languages because the specific vocabulary simply doesn't exist.
例如，气味不同于颜色，在许多语言中无法命名，因为特定的词汇根本不存在。
《剑桥雅思真题8》Test 3 Passage 3
In comparison to the life span, this relationship is ‘inverted'.
与寿命相比，这种关系是“颠倒的”。
《剑桥雅思真题10》Test 2 Passage 3
By contrast, the audience encounters an opera or a play over a specific time, which is the duration of the performance.
相比之下，观众会在特定的时间内看到一部歌剧或一部戏剧，也就是演出的持续时间。
《剑桥雅思真题8》Test 2 Passage 3
While it is true that the olfactory powers of humans are nothing like as fine as those possessed by certain animals, they are still remarkably acute.
诚然，人类的嗅觉能力远不如某些动物的灵敏，但它们仍然异常敏锐。
《剑桥雅思真题8》Test A Section 3
Most European studies have used liquid concentrates extracted from the tops of plants, whereas extraction in the USA has usually been from the roots.
大多数欧洲研究都使用从植物顶部提取的液体浓缩液，而美国的提取液通常是从根部提取的。
《剑桥雅思真题5》Test 1 Passage 1
He was also helped by six assistants, two of whom died whilst the Dictionary was still in preparation.
他还得到了六名助手的帮助，其中两名助手在词典编写期间去世。
《剑桥雅思真题4》Test 1 Passage 2
By comparison, the bottlenose dolphin has extremely keen vision in water.
相比之下，宽吻海豚在水中的视觉非常敏锐。
9．表举例：for example, for instance, such as, take ...for example, to illustrate, say。
《剑桥雅思真题7》Test 2 Passage 2
In Britain, for example, many of our best-loved farmland birds
例如，在英国，我们最喜爱的许多农田鸟类
《剑桥雅思真题12》Test 5 Passage 2
They'll look for, say, antiques that they can buy cheaply and expect to be able to sell at a profit.
比如，他们会寻找能够以较低的价格购入的古董，并期望卖出后获利。
《剑桥雅思真题12》Test 5 Passage 2
Stamp collectors, for instance, arrange their stamps in albums.例如，集邮者，在相册中摆放他们的邮票。
《剑桥雅思真题12》Test 6 Passage 1
Farmers everywhere face major risks, including extreme weather, long-term climate change, and price volatility in input and product markets.
世界各地的农民都面临着重大风险，包括极端天气、长期气候变化以及输入和产品市场的价格波动。
《剑桥雅思真题9》Test 3 Passage 2
Undersea turbines could become a big export earner to island nations such as Japan and New Zealand.
海底涡轮机可能成为日本和新西兰等岛国的主要出口来源。
10．表同步：at the same time, in the meantime, meanwhile。
《剑桥雅思真题11》Test 1 Passage 3
Meanwhile in the Russian Arctic, geo-engineering plans include the planting of millions of birch trees.
与此同时，在俄罗斯的北极地区，地球工程计划包括种植数百万棵白桦树。
《剑桥雅思真题7》Test 3 Passage 3
At the same time, forests provide raw materials for human activities through their constantly renewed production of wood.
同时，森林通过不断更新的木材生产为人类活动提供了原材料。
11．表顺序：first, second, third, then, finally, to begin with, first of all, in the first place, last, next, last but not the least, first and most important。
12．表可能：presumably, probably, perhaps。
《剑桥雅思真题10》Test 3 Passage 2
If insects paid attention to such advertisements, they might be prompted to lay their eggs on a duller, and presumably less resistant host.
如果昆虫注意到这样的广告，它们可能会被提示将卵产在较迟钝的寄主身上，而这种寄主的抵抗力可能较弱。
《剑桥雅思真题7》Test 4 Passage 3
Probably the most significant finding from research on noise is that its predictability is more important than how loud it is.
对噪音的研究可能最重要的发现是，噪音的可预测性比噪音的大小更重要。
《剑桥雅思真题7》Test 1 Passage 3
We can, perhaps, attribute mediocre results to an inadequate placebo effect.
也许，我们可以把平庸的结果归因于安慰剂效应的不足。
13．表解释：that is, namely, in simpler terms。
《剑桥雅思真题12》Test 5 Passage 2
There are the people who collect because they want to make money—this could be called an instrumental reason for collecting; that is, collecting as a means to an end.
有人收藏是因为他们想赚钱——这可以被称作收藏的工具理性；也就是说收藏行为是一种达成结果的工具。
《剑桥雅思真题11》Test 2 Passage 1
This led to an important decision being taken: namely to carry out the lifting operation in three very distinct stages.
这导致了一个重要的被采纳了的决定：即在三个非常不同的阶段进行起重操作。
14．表让步：although, after all, in spite of, despite, even if, even though, though, admittedly。
《剑桥雅思真题12》Test 5 Passage 3
After all, a subject matter can have principles in the sense of being codified, having rules, as with football or chess, without being principled in the sense of being ethical.
毕竟，一门学科从被编辑，从规则的意义上而言可以是有原则可循的，正如足球和国际象棋那样，而从伦理的意义而言，是没有原则可循的。
《剑桥雅思真题5》Test 3 Passage 3
Admittedly, the rehabilitation of the term has a long way to go.
诚然，这个术语的恢复还有很长的路要走。
《剑桥雅思真题8》Test 2 Passage 3
In spite of its importance to our emotional and sensory lives, smell is probably the most undervalued sense in many cultures.
尽管嗅觉对我们的情感和感官生活很重要，但在许多文化中，嗅觉可能是最被低估的。
15．表原因：for this reason, due to, thanks to, because, because of, as, since, owing to。
《剑桥雅思真题12》Test 5 Passage 1
Recent years have seen the end of the virtual monopoly of cork as the material for bottle stoppers, due to concerns about the effect it may have on the contents of the bottle.
近年来，由于担心瓶塞对瓶子中装的东西的影响，软木塞作为瓶塞的主要材料，其实质垄断已经结束。
《剑桥雅思真题7》Test 1 Passage 2
The amount of water consumed per person has actually decreased, thanks to a range of new technologies that help to conserve water in homes and industry.
由于一系列的新技术帮助家庭和工业节约用水，人均用水量实际上已经减少了。
《剑桥雅思真题11》Test 1 Passage 2
The Wheel could not be constructed to elevate boats over the full 35-metre difference between the two canals, owing to the presence of the historically important Antonine Wall.
由于历史上重要的安东尼墙的存在，车轮无法提升船只通过两条运河之间整整35米的差距。
《剑桥雅思真题11》Test 1 Passage 1
The concept of indoor farming is not new, since hothouse production of tomatoes and other produce has been in vogue for some time.
室内种植的概念并不新鲜，因为温室生产的西红柿和其他农产品已经流行了一段时间。
《剑桥雅思真题11》Test 1 Passage 1
However, more often than not now, due to a rapidly changing climate, that is not what happens.
然而，由于气候的迅速变化，现在的情况往往不是这样。
《剑桥雅思真题9》Test 3 Passage 1
Because her father lost his savings through bad investment, she then had to take work as a teacher.
因为她的父亲因为投资失败而失去了积蓄，所以她不得不去当老师。