We use the present perfect tense to talk about things where there is a connection between the past and the present.
我们用现在完成时态谈论那些过去和现在有联系的事情。
• He’s written 16 books.
He started writing books at some time in the past. So far, he has written 16 books. He may write more books.
他过去有段时间写书。到目前，他已经写了16本书。他可能写更多的书。
As well as the present perfect simple, we can use the present perfect continuous tense to talk about events with a connection to the present.
就跟现在完成时一样，我们也用现在完成进行时态去谈论和现在有联系的事情。
1 Look at these 2 sentences:
1 看下面两个句子：
• I’ve been decorating the house this summer. The focus is on the action – decorating – and the action is unfinished.
• I’ve painted the living room blue. The focus is on the finished result. The activity is finished but we can see the result now.
We use the present perfect continuous when the focus is on an activity that is unfinished.
当句子重点是在还没完成的事情上的时候，我们用现在完成进行时。
2 Look at these two sentences.
2 看下面两个句子：
• I’ve read that book you lent me. I finished it yesterday.
• I’ve been reading that book you lent me. I’ve got another 50 pages to read.
The present perfect simple (I’ve read) gives the idea of completion while the present perfect continuous (I’ve been reading) suggests that something is unfinished.
现在完成时例句I’ve read是表示完成的意思，而现在完成进行时I’ve been reading则暗示事情还没完成。
3 Look at these two sentences.
3 看下面两个句子：
• She’s been writing emails for 3 hours.
• She’s written 10 messages.
The present perfect continuous (has been writing) talks about how long something has been happening. The present perfect simple (has written) talks about how much/how many have been completed.
现在完成进行时has been writing谈论的是某事已经发生了多长时间，而现在完成时has written强调的是某事已经完成了多少。
4 Look at these two sentences.
4 看下面两个句子：
• I’ve worked here for thirty years.
• I usually work in London but I’ve been working in Birmingham for the last 3 weeks.
We can use the present perfect simple to talk about how long when we view something as permanent. But the present perfect continuous is often used to show that something is temporary.
我们用现在完成时谈论某件长久的事情。而我们用现在完成进行时表示某件暂时的事。