수고 [ sugo ]
수고 means ‘effort or/and energy to do something’ or ‘difficulties to do something’.
Koreans use this expression to show that they acknowledge the effort, energy, or difficulties of the listener, and to encourage the listener to continue the hard work.
For a good example, when Koreans visit where someone is working or practicing hard, they say 수고 많으십니다 [ sugo maneusimnida ] (a polite way), meaning ‘you are working very hard’, as a hello.
Examples below are used after something is done by the listener.
수고했어. [ sugohaesseo ] (You did a good job.) (between friends)
수고하셨습니다 [ sugo hasyeotseumnida ] or 수고 많으셨습니다 [ sugo maneusyeotseumnida ] (you worked so hard) (to be polite)
* 수고 cannot be used to higher person as imperatives.
수고해. (Keep working hard) (between friends) O
수고하세요. (Keep working hard) (to a higher person) X