From my experience, I find that a lot of students are lazy, don't pay attention during class time and don't want to do the set homework.

First I think that It's probably from the lack of spending time for studying it and second is the most important thing regarding to learing something is from teacher.

No practice or commitment. The moment a student exits the class, he forgets about English and goes back to speaking Spanish. He feels he has no need for it. Create a need for English and you will create a desire to learn English.

Poor teaching levels and very limited practice in real life.