The present perfect tense has a number of uses.

现在完成时态有许多使用方法。

1 We use it to talk about experience.

1 我们使用它讨论经验

• I’ve worked in 6 different countries.
• Have you ever been to Australia?
• She’s won many awards for her books.

When these things happened is not important – the focus is on the action/state, not when it happened.

这些事情什么时候发生的并不重要，关键是现在的状态，而不是什么时候发生的。

If we say when we had the experience, we must use the past simple.

当我们说我们什么时候有的这个经验，我们必须使用一般过去时。

• I’ve visited Russia several times.
• BUT I visited Russia for the first time in 1992.

We can never use the present perfect with a time in the past.

在有过去的时间时，我们不能用现在完成时。

• I have been to Spain in 2002.

2 We also use the present perfect to talk about things that are unfinished – unfinished states and unfinished time periods.

我们也用现在完成时表述未完成的事情——未完成的状态和未结束的时间区间

• I’ve known him since I was 11. (unfinished state)

I met him when I was 11. I still know him now. The present perfect is acting as a bridge between the past and the present.

当我11岁时，我见到他。我现在仍然知道他。现在完成时就像一个过去和现在的桥梁。

• I’ve had this watch for almost thirty years.
• We’ve lived here since I was a boy.
• She’s been to the cinema three times this week. (unfinished time period)

This week isn’t finished yet – she may go to the cinema again.

本周还没有结束——她可能还会去电影院。

• We’ve already had two holidays this year.
• I’ve eaten too much today.

3 A third use of the present perfect is to show the present result of a past action

3 现在完成时的第3个用法是展示过去行为的现在结果。

• I’ve lost my keys.

He lost his keys some time in the past but the result – he can’t get into his house – is in the present.

他过去某段时间丢了钥匙，但结果是在现在——他不能进入房间。

• John’s broken his leg and he can’t go on holiday.
• A storm has blown down the telephone lines. We’re stuck here!