If I understand English phrases right then "it is still going to rain" is все еще собирается дождь or дождь все еще собирается пойти (the rain didn't started yet) and "is it still raining " is дождь еще идет or все еще идет дождь (the rain have already started but haven't stopped yet).
Each language has its own logic. It is a general fact you have to accept and even welcome, when you learn foreign languages. It is much more fun that way. Why do you say "help yourself" in English? In most languages, it doesn't make sense. You help others, not yourself :) There's a different verb for things you do for yourself.