I have been teaching English for seven years, and I have discovered many different kinds of students. Ones are really keen on learning. Others they do it (as mandatory) because they have to, and this is the main reason for abscence and quitting.
The ones that they really want to learn, they learn it in a very fast way. They think is more like a pleasure to do it. Usually, I have seen that they are the ones who have travelled to other countries and they use it in their daily lives;listen to music, watch tv, have friends from other countries, like to travel etc. For them is a constant interest to have a every day a better level of English. Of course for an English teacher this is completely an ideal group. Everybody participating, interest in new words etc. But this is not the real truth.
The second group is usually common to find. They go to learn because of their work or because of their studies but they don not feel it. They usually had a a bad experience with other teachers and methodology. For them is a like a "karma" to do it. As a teacher for me this is the challenging part. It is important to motivate them to do it but how? Firstly, all is your attitude as a teacher. You must be optimistic and really feel it as a passion to teach. Secondly, methodology is important. I think you must teach in an easy way with out using so much terminology, and also to have good material such as good books, activities; lots of them!!! and be interactive. Actually, I have discovered that students are interested in applying technology to their language learning process. Trying to use mobile phones, internet, email etc motivate them more to learn. Finally, find a catchy topic and apply it to the class. You must understand that person feelings, interest, daily life.