The reason for this is that ...（原因解释） The cause of this is that ... (同上) There are three reasons for this. First， Second， Third 这些是一些基本的句型，同学们可以记一下。然后举几个例子加深理解。 举例： 1 The reason why she didn't go was that she was afraid. 她没去的理由是她害怕。
2 He didn't finish the exercise because he wasn't given enough time. 他没有做完练习是因为时间不够。 3 My uncle died last year， the reason for which was a car accident. 我叔叔去年去世了，原因是一场车祸。 4 There were few guests at the party yesterday because it wasn't Sarah's birthday. 上个星期天聚会客人不多，因为不是萨拉的生日。 5 I didn't bring my textbook to class today and the teacher asked me to explain how to solve this problem.我今天的课本没带，老师让我解释如何解题。
6 They delayed the start of play until everyone was ready.他们延迟了开始比赛的时间，直到每个人都准备好。 7 We stopped talking about it because we weren't sure if there were other people who wanted to know more. 我们没有再谈论此事，因为我们不确定是否还有其他人想了解更多信息。
8 You need to return your library books by tomorrow because otherwise you will have to pay late fees. 你需要明天归还图书馆的书籍，否则你将付违约金。
下面我们来看具体的例句：As China is a more powerful nation， Chinese is being considered as an international language. 由于中国是越来越强大的国家，汉语作为一门国际语言正被提上日程。（as引导的原因状语从句置于主句前）They have to stay indoors， because it is raining outside. 由于外面下着雨，他们不得不待在家里。[because引导的原因状语从句只有置于主旬后]
采用这样的方式来表示因果关系是需要记住相应的前后分句的句式。对于“原因：结果”这样的关联需要记住的结构是the reason is that...; for this reason， ; this is because…. 举例来说：The price of oil has continued rising for four months in a row， which has upset the general public quite drastically. The reason is that the output of oil has greatly declined over the years with few new sources of oil being discovered. 过去的4个月里油价不断地上涨，这给普通民众带来了很大的冲击。原因就是石油产量下降了很多，而被新发现的石油源却很少。而“结果：原因”的关联需要记住的结构有，owing to/the consequence is that... 这种标点符号+从句的方式来表示因果关系与连词+从句的方式不同，它前后是两个分句，即句子的前面与后面都可以独立成句，所以用标点符号来连接，而前面讲述的连接副词+从句的方式前后不是独立的句子，需要用连接副词来连接。
方式三：并列句
并列句中表因果关系的连词常用的有：therefore， thus， consequently， as aresult， so， which， that’s why。在使用这些词语的时候，要注意前后分句是否可以独立成句，如果不能，前面加一个it is... 结构。因为并列句是表示同等重要的两个分句，如果前句主语是人，那么，就必须使用it is...。例如：It is air pollution caused by cars which， therefore， is the major problem of our society nowadays. 是由于汽车造成的空气污染，因此是现代社会的一个主要问题。
