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"?
- from the high position looking down
When the verb denotes upward action or direction, and the object denotes 'comparatively high position', '上' means 'up to (successfully)'
Example:
登山顶 - reach the mountain top (登 shows you are attempting to reach the mountain top, but doesn't clearly indicate you have done so successfully)
登(上)山顶 - reach (up to) the mountain top (登上 indicates you not only attempted, but also successfully reached up to the mountain top)
爬河堤 - Climb the river embankment (爬 shows you are attempting to climb an embankment)
爬(上)河堤 - Climb (up to) the river embankment (爬上 indicates you not only attempted, but also successfully climbed up to the embankment)
- presents the result of the action:
When the verb denotes 'applying', '上' denotes 'onto successfully'
Example:
穿外衣 - wear jacket (the action 穿 must be applied to a body)
穿(上)外衣 - wear jacket onto (上 shows the verb 穿 is successfully applied onto a body)
寫四個字 - write four words (the action 寫 must be applied to a surface)
寫(上)四個字 - write four words onto (上 shows the verb 寫 is successfully applied on to a surface)
- presents the beginning and continuation of the action:
when the verb implies it is an ongoing action
Example:
她爱草原 - she loves grassland (the action love is a continuous action. )
她爱上了草原 - she fell in love with grassland (上 show the beginning of the verb 爱, and the verb 爱 itself is a continuous action)
吃上饭 is not an example for 'verb that indicates successfully apply'. It is an example for 'verb that indicate successfully acquire'
吃饭 - eat meal
吃(上)饭 - (successfully) eat (acquired) meal
