keep doing 和keep to do的区别

keep doing, keep on doing
keep doing表示不间断地做某事;keep on doing表示动作是时断时续的。

这两个词组均用来表示“不断做”的意思，但在涵义上有所不同。

1. keep doing和keep on
doing都可表示“不断（老是）做某事”的意思，强调动作连续不断，每隔一会儿发生，这时两者可以换用。不同的是keep doing中的doing是动名词，作宾语。例如：John always kept (on) asking questions.
约翰总是问个不停。
News of successes keeps (on) pouring in.
捷报频传。

2. keep doing还可表示连续不断的动作或持续的状态。keep on doing则没有这种用法。例如：
We kept working in the fields in spite of the rain.
尽管下雨，我们还是坚持在地里干活。
Why do the dogs keep barking?
这些狗为什么不停地叫？

【keep（on） doing】:to continue doing sth,to do sth repeatly 继续，重复做某事，介词on可省可不省，都对

例句：Keep smiling！保持微笑
例句：Don't keep on interrupting me! 别老是跟我打岔

【keep to sth】:
1 > to avoid leaving a path,road 不偏离道路
例句: Keep to the track——the land is very boggy around here.顺着道走，这一带都是沼泽地。

2 > to talk or write only about the subject that you are supposed to talk or write.不偏离主题，不跑题
例句：He is a person who does not keep to the point. 他是一个说话不着边际的人。

3 > to do what you have promised or agreed to do 信守、履行诺言
例句：Please keep to the agreement. 请遵守协议

4 > to stay in and not leave a particular place or position 坚守、不离开（某地、某位置)
例句：She mostly keeps to her room.她大部分时间都呆在房里。

【补充】keep to 的 "to "是介词，没有"keep to do "这种形式

keep doing是一直做某事，但是好像没有keep to do这个用法，我再查查给你答复，呵呵