标志：have / has + 动词的过去分词
He has left the city. （结果：他目前不在这个城市）
Someone has broken the window. （结果：窗户破了）
I have been busy since last week.
He has taught in our school for 30 years.
I’ve finished half so far.
She hasn’t seen you for ages.
His father hasn’t touched beer for a whole week.
3. 表示过去到现在为止反复发生的动作或多次出现的状态，常与表示频度的副词always, often, every day等连用。如：
I have often heard that he is the cleverest person in that company.
I’ll go to your home when I have finished my homework.
If it has stopped snowing in the morning, we’ll go the park.
能与现在完成时连用的词语很多，just, already, yet, before, never, ever, recently等，但常见的有：
1) since 自从
I have been there many times since the war.
We haven’t seen each other since last week.
We have been friends ever since.
2) in / for / during the past/last … years 在过去/最近…中
I’ve been ill for the past three weeks.
Great changes have take place in the last ten years.
I have been here (for) the last/past month.
3) so far 到目前为止
We haven’t had any trouble so far.
So far the search for the missing middle-aged woman has been fruitless.
4) up to/until now 到现在为止
Up to now he’s been quiet.
Up to now, the work has been easy.
I have heard nothing from him up till now.
Up till now we have planted over 2000 trees.