1. keep at sth 坚持做某事。
如：Keep at it. 坚持做。
He kept at the job until finished. 他坚持把工作干完。
2. keep doing sth
(1) 不断地或一直做某事(动作之间略有间隔)。
如：They kept talking about it. 他们一直在谈论此事。
My shoe laces keep coming undone. 我的鞋带老是松开。
注：此用法可与 keep on doing sth 换用。
(2) 一直在做某事(无间隔)。
如：He kept standing during the meeting. 开会时他一直站着。
He kept hoping that they would have chance to come to China some day. 我一直希望什么时候有机会到中国来。
注：此用法通常不能与keep on doing sth换用。
3. keep on doing sth
(1) 不断地或一直做某事(动作之间略有间隔)。
如：He kept on looking at us. 他老是瞧我们。
Dont keep on asking questions like that. 不要老是问那样的问题。
注：此用法可与 keep doing sth 换用。
(2) 继续做某事(即将一直在做的事继续做下去)。
如：He kept on working after dark. 天黑了我们还继续干。
Dont give up; keep on trying. 别灰心，继续努力。
注：这样的 keep on doing 有时可与 go on doing 换用。如：The boys kept [went] on doing their homework in spite of interruptions. 尽管有干扰，孩子们仍继续做自己的作业。
4. keep from (doing) sth
(1) 忍不住做某事。
如：I couldnt keep from laughing. 我忍不住笑了。
(2) 避开或防止(做)某事。
如：He keeps from bad company. 他不与坏人为伍。
He kept from talking about it. 他避而不谈此事。
5. keep sb fromdoing 使某人不能做某事。
如：The rain kept us from going out. 下雨使我们没法出去。
We must keep them from getting to know our plans. 我们一定不要让他们知道我们的计划。
6. keep sb (sth) doing sth 使某人(某事)不停地做某事。
如：He kept the fire burning. 他让火燃着。
Im sorry to have kept you waiting. 对不起让你等了。
7. keep sb (sth) done 使某人(某事)被。
如：Keep you mouth shut and your eyes open. 少说话，多干事。
She kept us supplied with food and money. 她为我们源源不断提供食物和钱。
8. keep back
(1) (使)后退。如：Keep back. 后退。The police kept the crowd back. 警察使群众后退。
(2) 忍住，隐瞒。如：She couldnt keep back her tears. 她忍不住哭了。Ill keep nothing back from you. 我什么也不瞒你。
9. keep down 抑制，控制，使下降。
如He couldnt keep down his anger. 他控制不了怒火。The government is trying to keep prices down. 政府正在设法降低物价。
10. keep off 避开，防止，挡住。
如：Danger, keep off. 危险，走开。
Please keep off that subject. 请避开那个话题。
He made a fire to keep off wild animals. 他烧了堆火使野兽不敢走近。
11. keep on 继续。
如：The rain kept on for several days. 雨一连下了好几天。
Keep on until you come to the station. 一直走到车站.
12.keep out 遮挡，使不进入。
如 ：The trees keep out the wind. 这些树可以挡风。
Warm clothing will keep out the cold. 暖和衣服可以御寒。
13. keep out of 使不进入。
如：Keep the dog out of my room. 别让狗进入我的房间。
Try to keep out of other peoples quarrels. 设法不要卷入别人的争吵。
14. keep up 保持，继续。
如：Rain kept up all night. 雨下了一整夜。
I hope the fine weather will keep up. 我希望好天气会保持下去。
15.keep up with 跟上，不落后。
如：Try to keep up with the others. 设法不要落在别人后面。
Its hard to keep up with the changes in computer technology. 要跟上电脑技术的发展不容易。