finish是瞬间动词，也叫非延续性动词。have finished并非是延续。而是指过去动作对现在造成的影响或结果。

finish

v.完成;做好;(使)结束;吃完，喝光，用尽(所剩之物)

n.最后部分;结尾;结局;末道漆;抛光

例句：

Pressure was brought to bear on us to finish the work on time.

我们得按时完成工作，没有回旋余地。

I need about an hour to finish off this report.

我需要一小时左右结束这篇报告。

As a matter of interest, what time did the party finish?

我想知道，晚会是什么时间结束的？

I didn't finish the test ─ I ran out of time.

我没答完试卷，我的时间不够了。

I went home directly I had finished work.

我一干完活就回家了。