During my experience of Teaching languages for other people or my student, what I found is that people learn the language because there are important in their life. It gives more scope for thier own career but thats the wrong way of learning. what I do is, before teaching, I make sure that they know the beauty of languages because you will only learn when you fall in love with it since anything that you dont like it becomes a burden. Everything becomes easier when you like it and focus on it, then the word will unboundly flow through you like a spring of mother nature.