Interesting this resembles a question I just asked. I think the answer really depends on how many students are not getting it, for instance if its a big group or the majority of the class, I think you should re-explain the idea, but not in a way that shows that the problem is coming from you or that you couldn't explain it properly, you could tell them " It's OK, I understand this is new for you, but let's think about it in another way" this will help remove the tension the students are growing from the fact that they aren't understanding what you're saying ! Now if the problem is only with one student, I say carry on with the lesson and when you give the students an exercise to do on their own, go to that student and quietly explain to him aside the idea in a way that he will definitely understand.
When confronting this kind of problems, the learner is often physically present but mentally absent, i think when mixing a little bit of fun with teaching, it makes the learning processes both easy for grasping and intresting for listening, and thus the learner/student will be more likely to enjoy the lesson and will be finally understanding your explaining.
Is it the terminology, choice of words or grammar or phrases that is causing the miscomprehension?
Is the idea that needs to be grasped adequately helped by the material?
Give students opportunity to demonstrate what they do understand.
Let the students discuss further areas where there is resistance to wanting to understand and this may reveal hidden fears, fear of failure, sensitivities, or other forms of resistance. Is there something really controversial that could come of the material which you are not aware of or considered?
In case of such issue, take a start of the lecture and start asking small bits of questions from the lecture so that u know that which is point or points confusing the student.
If trapped in this problem, know that you have to change your teaching system. No matter how rich is your lesson, students differ in terms of understanding abilities , because some students are auditive, some are visual and some are musical, etc so they will not grasp everything you try to pour in their brains with the monotonous way you adapt in teaching.. so you 'd better to change the teaching method everytime to let the lesson understood for all students
We can deal with this matter by changing the way that the teacher is explaining the lesson by it.
The way the teacher is depending inside the classroom has an important side for students to understand the lesson.
