One insight that I have gained when it comes to language learning can be divided into four parts: speaking, listening, writing, and reading. They can also be divide into 2 categories: conversational and formal. To most learners' intuition, speaking and listening fall into the first category. For conversational, my insight would be that one can only improve and qualify himself as someone who knows the language by excessively exposing himself to speaking and allowing mistakes if the language is not a dead language like Latin or Sanskrit. Through allowing mistakes, one will become familiar with his weakness and also receive alert from the brain when the next time similar situation occurs. Moreover, the process of speaking involves a listener, which implies that whenever speaking happens, so does listening. The two are auxiliary. Although the second category is more formal and for academic use, it is the fundamental of the language learning. Since without knowing how to read and write, one is not able to produce text and once, speaking or listening are not possible (pen pal or international phone call). Thus, writing and reading are also crucial.
To me, I find it most difficult to perfectly speak one language since the rest of the three can consult sources. Writing and reading can be assisted by dictionary. As for listening, people can always repeat when they talk. Yet, the only thing that no one can help you is finish your sentences in a conversation. I enjoyed learning how to speak fluently and listen as precisely as possible for I learn Italian mostly for travel purposes.
