SectionAGrammarfocus4a—4b-(11)VIP免费

The PresentThe PresentPerfect Tense 1. 现在完成时态表示过去发生的动作对现在造成的影响或结果 Our teacher has left. We have studied English. I have already finished the homework. He has had his lunch. He has become a doctor.have/has+ 过去分词 2. 某个动作从过去已经开始 , 一直持续到现在 , 还有可能持续到将来 . 动作的持续性要通过一段时间来表示 .一段时间的表达方法有两种 :for: + 一段时间 for a year for two weeks for three yearsSince 过去的某一时刻 , since nine since last week 一般过去时态的时间状语从句 since you came since you got home.注意 :for 和 since 所引导的时间状语都表示一段时间 .He has been away since last week.He has been away for one week.对划线部分提问都用 How long The Past The Past Perfect TensesNew 现在完成时：现在完成时：助动词 have have // has has + 过去分词过去完成时：过去完成时：助动词 hadhad + 过去分词 构成？ 我认识他三年了。我认识他三年了。 I have known him for I have known him for three years. three years.  I had known him when I I had known him when I was a student.was a student.我当学生时，就已经认识我当学生时，就已经认识他了。他了。had knownhad known have knownhave known waswas  我已经做完作业了。我已经做完作业了。表示在说话时已经做完。表示在说话时已经做完。I I have finishedhave finished my home- my home-work.work.  在六点以前，我就已经在六点以前，我就已经完完 成作业了。成作业了。ByBy six o’clock, I six o’clock, I had had finishedfinished my homework. my homework. 表示在过去的某一段时间表示在过去的某一段时间（（ six o’clock six o’clock 以前）以前）已经已经做完作业，与现在无关。做完作业，与现在无关。  他们已经吃过早饭了。他们已经吃过早饭了。 在他们到旅馆之前他们在他们到旅馆之前他们已已 经吃过早饭了。经吃过早饭了。They They havehave already already hadhad breakfast.breakfast.They They hadhad already already had had breakfast breakfast beforebefor...