I teach much older students (9th and 11th grade), but I have found that the key to keeping them engaged is to gear the instruction towards something that is important to them; just because we as teachers must convey a certain amount of content doesn't mean that it has to be presented in a stuffy, "direct instruction" kind of way.

In order to facilitate this, you should decide what it is that you want them to learn, and try to see how this is applicable to life at their level. For your students it may be linking English to social and cultural settings that they are interested.

Once they make this connection, their interest increases, and they approach the topic with a great deal more enthusiasm; once this happens, the teachers job is to praise their progress, and encourage further learning through leading questions and discussions. I have found this to be far more effective than more traditional methods.