保持用英文怎么说过去式

"kept"是"keep"的过去式，来源于古英语"cypan"。

例句：

I kept the secret for her. (我为她保守秘密。)
He kept his promise to his parents. (他信守跟父母的诺言。)
She kept her diary under lock and key. (她把日记锁起来保存。)