Why is "Все плохо а я знаю, что делать." incorrect? This sentence seems to have a contrast which would suggest the use of 'a' rather than 'но' as given in the correction. Thank you.
It is not a contrast. It is more like having an ability to change something. For example, "Everything is bad but Tom is happy" has a contrast, and can be translated with "а", but not the sentence in the task.
"все плохо, зато знаю что делать"?
This is an excellent political slogan.
when is it делать and when сделать