Learning English is both. When you take the time to learn how to speak another language, that act of learning creates knowledge about that language or what it takes to communicate in that other language. Comprehension and spoken abilities are achieved at different rates depending on the learner, but fluency usually entails knowledge as well as skill. And speaking another tongue is an amazing way to develop critical thinking skills; because languages employ different methods of syntax and grammar, studying one teaches you how closely aligned words can...