(a) not wander from or leave (a path, road, etc) 不偏离, 不离开（道路等）
*Keep to the track the moor is very boggy around here. 不要偏离车道--这一带沼泽地多.
* (fig 比喻) keep to the point/subject 别扯远了[不要离题].
(b) follow or observe (a plan, schedule, etc) 遵循, 遵守（计划、时刻表等）
*Things will only work out if we all keep to the plan. 只有大家执行计划, 事情才能成功.
(c) remain faithful to (a promise, etc)忠于, 信守（诺言等）
*keep to an agreement, an undertaking 信守协定、承诺.
(d) remain in and not leave (the specified place or position) 留在, 不离开（某地或某位置）
*She's old and infirm and has to keep to the house. 她因年老体弱而足不出户.
(e) (used esp in the imperative when rebuking sb 尤用于祈使语气以指责某人) not express (a comment, view, etc) 不必说出（意见、看法等）
*Keep your opinions to yourself in future! 你有意见留　自己用吧! keep (oneself) to oneself avoid meeting people socially; not concern oneself with other people's affairs 不与人交往
*Nobody knows much about him; he keeps himself (very much) to himself. 谁都不太了解他, 因为他很少与人来往. keep sth to one`self not tell other people about sth 不把某事告诉别人
*I'd be grateful if you kept this information to yourself. 这事你若能保密则不胜感激.