Grammar is sometimes known to be not so interesting . . .
I must disagree, though, because in most cases I find grammar absolutely fascinating. :-)
But if you, or your students, are not in the same opinion as me, there are some things you can do to increase interest and involvement (not to mention results!):
Make sure the student understands all the words and terms in the subject you are trying to teach.
Incorrect example: teaching the passive voice without explaining what "voice" actually means in this context.
Correct example: explaining what a "voice" means first. Also, make sure the student fully understands the terms SUBJECT and OBJECT, since they will encounter them shortly
And by the way, a voice in this context means:
The form of a verb that shows whether the subject of a sentence performs the action or is affected by it.
If it performs the action - we call it the active voice.
If it is affected by the action - we call it the passive voice.
There are more tips to come.