一、句点 1.句点用于当一句话完全结束时。 2.句点也可以用于英文单词的缩写。如：Mrs. | Dr. | P.S. 等。但要注意的是当缩写的字母形成了一个单词的时候就不要使用句点。如：IBM, DNA 等。 二、问号 问号要用在一个直接的问句，而不是间接的。 如：How will you solve the problem？是正确的用法，但用在I wonder how you will solve the problem？就不对了，应该使用句点而不是问号。 另外，在客气的用语中，也是用句点而不是问号。如：Will you please give me a call tomorrow. 三、感叹号 感叹号用于感叹和惊叹的陈述中，在商业写作中要注意感叹号的应用，因为不恰当的使用会显得突兀及不稳重。 四、分号 1.与中文一样，分号用于分隔地位平等的独立子句。在某些情况下，使用分号比使用句点更显出子句之间的紧密联系，另外分号也经常与连接副词thus, however, therefore一起使用(放在这些词语之前。 如：I realize I need exercise; however, I’ll lie down first to think about it. 2.在句子中如果已经使用过逗点，为了避免歧义的产生，就用分号来分隔相似的内容。 如：The employees were Tom Hanks, the manager; Jim White, the engineer; and Dr. Jack Lee. 需要注意的是：一个完整的句子以大写字母开始，以句点结束。写英文时用逗点代替句点、分号、冒号或破折号叫“逗号错”，这正是中国学生所要避免的。 请比较下列例句： 错：It was raining hard, they could not work in the fields.
（上面句子中划横线的部分是两个不同的主语，而且逗点前后的句子是完整的-----单独拿出来都能代表一个完整的意思。因此，用逗号违反了英文规定，即一个句子只能有一套主干。） 对：It was raining hard; they could not work in the fields. It was raining hard. They could not work in the fields. It was raining so hard that they could not work in the fields. They could not work in the fields because it was raining hard. It was raining hard, so they could not work in the fields. As it was raining hard, they could not work in the fields. 错：The essay is poorly organized, there is no central idea. 对：The essay is poorly organized; there is no central idea. The essay is poorly organized: there is no central idea. 五、冒号 1.冒号用于对后面内容的介绍或解释。如：This is her plan: go shopping. 2.冒号用于名单之前，特别是一个竖排的名单。 We transferred three employees tonew branches: ·Tony Wang to New York City ·Mike Jackson to Tokyo ·Mark Foster to Paris 当名单横排的时候，冒号要用在一个完整的句子之后。如：We need seven people: three students, three engineers, and a professor. 3.冒号用于一个正式的引用之前。 如：The professor said: “It was horrible.” 4.冒号也可用于商业或正式信函的称谓后面。
