以下内容摘自下期将发布的《经济学人》双语文章中的第一段，本期主要讲下并列连词and、but和or等是否可以置于句首的问题。
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对于and、but、or、so这些并列连词能否放在句首，尽管在《经济学人》等其它顶级杂志中经常看到，但是很多人对这个用法还是颇有疑问的，因为确实有不少出处对不能将并列连词置于句首的情况作出了说明，比如在wikihow网站上就说：
Do not start a sentence with a coordinating conjunction.In the written language, do not use coordinating conjunctions such as 'and,” 'but,' “so,” or “or” to start a sentence. Coordinating conjunctions are meant to join words, phrases, and clauses; a coordinating conjunction is left dangling without a role to play when it comes at the beginning of a sentence.在书面语言中，不要使用并列连词and，but，so，or 等开始一个句子。并列连词是用来连接词语和从句的，当并列连词用在句首时，就无法实现它的作用。
放在句首到底可不可以呢？答案是肯定的。我们分别看看CMOS（The Chicago Manual of Style [芝加哥格式手册]）、权威词典以及一些专业英文学习网站的说明。
CMOS
5 : Grammar and Usage
5.191 Beginning a sentence with a conjunction
权威词典与专业英文学习网站
From http://www.oxforddictionaries.com/words/conjunctions
还有《美国传统词典》中也有相关的说明。
“But may be used to begin a sentence at all levels of style.But 可以放在所有文体标准的句子开头。”
这个话题产生的原因是因为，在19世纪的时候，当中小学教师告诫学生将并列连词置于句首这种情况不能过度使用时，总有一些学生可能还是会造出这样的句子：
And then I went to the park. And my friend Paul was there. But he had to go home for his tea.And then I was lonely so I went for a walk. And then I found a toy someone had left behind.
为了防止这种滥用的情况发生，对于某些规定难以把握和解释清楚的情况，老师就干脆采取强制性的规定：“同学们，以后不准将并列连词放在句首，就这么简单”。这种强制性的规定可能会比循循善诱的效果可能会好很多（我们很多时候就是这样被教育的），所以就有了这种“不能将并列连词放在句首”的说法。
但是要值得注意的是，and、but和or等并列连词放句首时，并列连词跟上文必须构成严谨的逻辑关系，不能显得过于突兀，恰当的运用并列连词作为开头可能会获得更强的效果，我们来看看Grammar Girl网站上有关的示例：
① Squiggly turned in his application on time. But he forgot to include his application fee.
② Squiggly turned in his application on time, but he forgot to include his application fee.
③ Squiggly turned in his application on time. However, he forgot to include his application fee.
这三句话中，网站认为第②句比第①句所带来的转折和起伏感就没有那么强烈，因为第一个独立句的句号形成了较长的停顿，再来一个But，意思的起伏更加明显。但是，如果你觉得接受不了或者把握不住这种处理手法，采用第③句也是可行的方式。
另外首句都省略了主语he，相当于祈使句。
当然，如果你撰写的学术论文需投稿至较高级别的外文刊物，最好还是按照期刊编辑跟你提供的style来，不要过度使用这种方式。甚至一些保守人士也认为不要赶这趟浑水，还是不要将并列连词放在句首。
“Still, not everybody loves initial but. The authors of Keys for Writers (2014) note that 'some readers may raise an eyebrow when they see and or but starting a sentence in anacademic paper, especially if it happens often.' So if you don't want to see eyebrows raised, ration your use of these words at the beginnings of sentences. ”
——摘自http://grammar.about.com/
但是从属连词是肯定不能单独置于句首的，其中的原理我在这篇文章中详细说过，请没有看过的同学点击查看：
【不掌握这些英文句法规则，你永远不知道自己有多搞笑|大话英文语法（1）】
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