You can say that you are fluent in i.e. english even if it takes you some effort to formulate some arguments. I'd say you are fluent in a programming language i

You can say that you are fluent in i.e. english even if it takes you some effort to formulate some arguments. I'd say you are fluent in a programming language if you can effortlessly write a program even if it took some effort to solve the problems per se.