I look up in youdao and it says meanings of 上 as below :
(1) from the high position looking down: 登上山顶, 爬上河堤 (2) presents the result of the action: 穿上外衣, 没吃上饭 (3) presents the beginning and continuation of the action: 她爱上了草原。or 他拿起一把铲就干上了。
So, How can I know when to use 上 after a verb?
Because after reading the definition, I am still confused: to express 1st meaning, used verbs must show the upward direction of action? is 2nd meaning the same as "完"?