I have found by letting the students help with lecture and demostration helps with the student understand what I'm talking about. Let me give an example if a student tells me he doesn't understand or does not know what that means I will find another way of presentation. I have used noises hand gestures I have incorporated bring up students and making them part of the lecture. I usually get through to the student the one thing I want to emphasize is do not embarrass the student. I have told the class if you do not under stand if I have gone over it ten times I'll go over it another ten times when I look around the room asking if you understand just give me a signal a nod a hand gesture and I'll go over it again because you're probably not the only one. If I need to tutor I will do that too.