过去完成时有两种情况:第一种情况是有两个动作,这两个动作都发生在过去,两个动作对比在先的那个要用过去完成时。举例子来说:i didn't know you had visited London before.在这句话中有两个动作一个是know 一个是visit;visit发生在先,know发生在后,所以visit就用了过去完成时,表示过去的过去。
第二种情况是有明确的过去时间状语,即动作发生在过去时间之前。举例来说:he had finished his job by the end of last month.在这个句子中the end of last month 是过去的过去,所以句子用过去完成时。by+过去时间状语是过去完成时的标志。
现在来说说现在完成时,现在完成时是过去的动作对现在产生影响,常常汉语中翻译成“已经..."在英语中就可以用现在完成时。 i have finished my homework.我已经完成了作业。
标记过完和现完的词组很多,很难区分怎么办
追答怎么能多呢?就按我上面给你的就可以了。
在一个明确的过去时间之前完成,并对当时长生影响,用过去完成时态.例如
i had finished my work when you came into the room.
he had went to sleep when you came back.
i had worked hard before i gratulated.
i had learned english for 30 years by the end of last year.
动作在过去发生,在说话时刻刚刚结束,并对说话时刻产生影响,用现在完成时态。时间多为
与现在有关的模糊过去点already yet ever just before recently lately
频度once twice three times some times many times time and time again
与过去有关的现在点时间now today tonight this morning this afternoon this evening this week this month this year
for+段时间 主句动词必具备延续性
all+段时间 主句动词必具备延续性
since+点时间 表示段时间 主句动词必具备延续性
so far until now up to now in the past/last 10 years 主句动词必具备延续性