参加KET/PET考试，只要制定好详细清晰的学习计划，科学有效备考，稳打稳扎学习，做好一切的考前准备，顺利通过考试不是个问题。邮件写作，不只是要考虑内容，还要注意时态。比如写一写当前正在做的事情，那么就要用现在进行时。瑞尔英语小编带你来一起学习信件的基本原则分析。
　　一、Courtesy 礼貌
　　语言要有礼且谦虚，及时地回信也是礼貌的表现。
　　例如：
　　We have received with many thanks your letter of 20 May, and we take the pleasure of sending you our latest catalog. We wish to draw your attention to a special offer which we have made in it.
　　You will be particularly interested in a special offer on page 5 of the latest catalog enclosed, which you requested in your letter of 20 May.
　　二、Consideration 体谅
　　写信时要处处从对方的角度去考虑有什么需求，而不是从自身出发，语气上更尊重对方。
　　例如：
　　"You earn 2 percent discount when you pay cash. We will send you the brochure next month. "就比"We allow 2 percent discount for cash payment. We won't be able to send you the brochure this month." 要好。
　　三、Completeness 完整
　　一封商业信函应概况了各项必需的事项，如邀请信应说明时间、地点等，确忌寄出含糊不清的信件。