1、4过去完成时与现在完成时的比较过去完成时与现在完成时的比较 I have known him for three years.我认识他三年了。 I had known him when I was a student. 我当学生时，就已经认识他了。 过去完成时与现在完成时二者用法基本相同， 但现在完成时以现在的时间为 基点，过去完成时则以过去的时间为基点，与现在无关，即过去的过去。 I have finished my experiment. 我已经做完实验了。 (表示现在说话时已经做完实验) By six oclock，I had finished my experiment. 在六点以前，
2、我就已经做完实验了。 (表示在过去的某一时间 six oclock 以前已经做完实验，与现在毫无关系) 注意注意 过去完成时，主要用于间接引语中。 必背！必背！ 易混词组 How long 多久 How often 多久一次 How far 多远 (只指时间，不指距离) (指频率) (指距离) How soon How many times (指多长时间) (指次数) 过去完成时与现在完成时的比较过去完成时与现在完成时的比较 练习题练习题 按要求变换句型 1Is Toms bike new?(肯定回答) 2There are come English books in the desk.(一般
3、疑问句) 3He has tea at half past two in the afternoon.(否定句) 4It will take the workers more than a month to repair the bridge. (对划线部分提问) 5I did my homework by myself yesterday.(一般疑问句) 6He had done with the goods before he went away.(否定句) 7The teacher was talking with Toms mother.(对划线部分提问) 8Im allowed to
4、 watch TV at home only once a week. (对划线部分提问) 【答案】 1Yes, it is 2Are there any English books in the desk? 3He doesnt have tea at half past two in the afternoon 4How long will it take the workers to repair the bridge? 5Did you do your homework by yourself yesterday? 6He hadnt done with the goods before he went away 7Whose mother was the teacher talking with? 8How often are you allowed to watch TV at home?
