你理解得對(duì).例子：I have been here for an hour.（我到這兒已經(jīng)有一個(gè)小時(shí)了.）He has been here for half an hour.（他到這里已經(jīng)有半個(gè)小時(shí)了.）I had been out when he came to see me.（他來(lái)找我時(shí),我已經(jīng)出門(mén)...knew him last year改為i had been kowing him last year?也可以改為i have known hom since last year?可以改為I have known him since last year. 但不能改為過(guò)去完成進(jìn)行時(shí)had been knowing。為什么?。磕浅擞胔ave加過(guò)去分詞的還能怎么做??？過(guò)去完成進(jìn)行時(shí)極少用到，在這里不適宜用，合適的例子一時(shí)難以找到。除了have known，還可以變?yōu)椋篒 knew him a year ago. 或者 I got to know him last year. 或者 I got to know him a year ago. 或者 I have known him for a year.i knew him last year改寫(xiě)為現(xiàn)在完成進(jìn)行時(shí)態(tài)怎么改？這樣改：I have been knowing him since last year. （自從去年起，我就認(rèn)識(shí)他。）