Good day!
Are these sentences acceptable?
1. "I'm sure you are doing a job well done.":cross:
I think 'a job well done' is for something that has been done already.:up: - 'done' is a past participle, and can't refer to the future (except in a specialized case like 'I want my steak to be well done.')
2. "You did pretty good." OK, but informal - it would be marked wrong in a written exam of academic English. More formally you would use 'well'. In an even less formal version, people referring to the performance of a footballer (or other sportsman) say 'the boy done good' (rather than 'did well').
Thank you for your help.