keep的过去式是kept
keep
英 [kiːp]
美 [kiːp]
v.保持;(使)处于;继续(做某事);使耽搁;保有;（为某人）保留，留下;放，存放，贮存（在某处）;开设，经营，管理（商店或餐馆）;养;健康状况如何;保持不坏;保守（秘密）;遵守;记下，记录，记载;供养;保护;守门n.生活必需品;生活费用;城堡主楼
例句
I said I'd go just to keep him happy. 我说过我要去只是为了让他高兴。
Keep down! You mustn't let anyone see you. 蹲下！一定不要让人看见你。
The most important thing is to keep yourself occupied. 最重要的就是别让自己闲着。