Keep的过去式是kept。

Kept的用法和常见搭配如下：

1. 主动语态

– She kept the door locked.

她把门锁上了。

– He kept the secret for years.

他保守了这个秘密多年。

– The company kept its promises.

公司履行了它的承诺。

2. 被动语态

– The children were kept in the room.

孩子们被留在房间里。

– The house was kept in good condition.

房子被保持得很好。

– The book was kept on the shelf.

书被放在书架上。

3. 搭配

– keep away：使远离

– The dog was kept away from the children.

狗被禁止接近孩子们。

– keep back：保留；阻止

– She kept back some money for emergencies.

她为紧急情况保留了一些钱。

– keep down：控制；压制

– The government is trying to keep inflation down.

正试图控制通货膨胀。

– keep off：避开；不接近

– Keep off the grass!

请勿草地！

– keep on：继续；继续穿着

– I’ll keep on working until the job is finished.

我会继续工作，直到工作完成。

– keep out：使在外；防止进入

– Keep out of trouble!

别惹麻烦！

– keep up：维持；继续

– They have kept up their friendship for many years.

他们保持了多年的友谊。

– keep up with：跟上；与……保持联系

– I’m trying to keep up with the latest news.

我正试图了解最新的新闻。

这些是kept的一些常见用法和搭配。在英语写作和口语中，正确运用这些搭配可以使句子更加丰富和生动。