keep的基本意思是“保留、保管、保存、留下、保持”，指使某人或某物继续保持某种状态。作及物动词，意为“保留、经营、养活”等。那么keep的过去式和过去分词是什么呢？

过去式：kept

过去分词：kept

第三人称单数：keeps

复数：keeps

现在分词：keeping

Your application will be kept on file. 

你的申请书将存档。

He kept us at it all day. 

他让我们不停地干了一天。

I go swimming every day in order to keep fit. 

我每天游泳以保持健康。

I can't keep up with all the changes. 

我并非所有的变化都能跟得上。

I said I'd go, just to keep him happy. 

我说过我要去只是为了让他高兴。

I'm sure she's keeping something back from us. 

我肯定她有什么事瞒着我们。

Keep that dog out of my study! 

别让那狗进我的书房！

We said we would keep them. 

我们说过要保存它们的。

Keep a note of where each item can be found. 

把每样物品的位置记录下来。

I'll keep you company while you're waiting. 

你等待时我会陪伴你。

Have an apple to keep you going till dinner time. 

吃个苹果就能挨到吃晚饭了。