Question

잘 했고, 잘 하고 있고, 잘 할 거야 In its 'and' meaning, -고 is used to list independent/parallel states or actions. When describing past situations, -고 can occur both with or without the past tense marker. The inclusion or omission of the past tense marker before -고 does not change the meaning of such sentences.

Accepted Answer

It was well done, you're doing well, and you're going to do well

Front	잘 했고, 잘 하고 있고, 잘 할 거야
Back	It was well done, you're doing well, and you're going to do well
Notes	In its 'and' meaning, -고 is used to list independent/parallel states or actions. When describing past situations, -고 can occur both with or without the past tense marker. The inclusion or omission of the past tense marker before -고 does not change the meaning of such sentences.

잘 고 Past Tense 했고 하고 있고 할