现在完成时
过去发生但与现在有联系：结果、经历或持续。
have / has + 过去分词
要点
- 表示过去发生的事对现在造成的影响或结果。
- 表示经历：常与 ever、never、before 连用。
- 表示持续：与 for、since 连用，动词要用延续性动词。
- 结构是 have / has + 过去分词。
- 三句"去过"各说各的事：He has gone to Shanghai（人去了还没回，不在现场）／ He has been to Shanghai（去过又回来了，现在在这儿讲经历）／ He has been in Shanghai for three years（一直待在那儿）。
- just、already、ever、never 卡在 have 与过去分词中间，yet 只进否定句和疑问句、排在句末：I have just come back. ／ Have you finished yet? ／ I haven't finished yet.
- 过去时间点一旦说死就得退回一般过去时：完成时不与 yesterday、last week、two days ago、in 2015 同框 —— I have seen the film yesterday 是错的。
- 配 for / since 要用能延续的动词或状态，瞬间动词得换一个说法：buy→have、die→be dead、join→be in / be a member of、borrow→keep、begin→be on。I have bought this bike for two years 不成立，写 I have had this bike for two years.
例句
Have you ever been abroad?
你出过国吗？
I have just finished reading this book.
我刚读完这本书。
I have been here for two years.
我在这里两年了。
We have been friends since childhood.
我们从小就是朋友。
He has gone to Beijing, so you cannot see him today.
他去北京了，今天你见不到他。
My father has had this car for ten years.
我父亲有这辆车已经十年了。
易错提示
- for 接时间段（for two years），since 接时间点（since 2010）。
- buy、die、leave 这类非延续性动词不能与 for / since 连用。
- 判据只有一条："过去那件事现在还管不管用"。管（结果、经历、持续）用完成时，只管把话说完就用过去时 —— He has lost his key（还没找到）／ He lost his key yesterday（找没找到，这句不管）。
- 完成时的 have 是助动词，三单换 has，后面那词必须是过去分词：He has wrote 错，写 He has written —— 分词栏单独记（write–wrote–written、speak–spoke–spoken）。