"I make you understand very well" - the verb "make" is not used in this context. You can make cookies, or you can make something better, but it is not typically used in this way. You could say: I will make you better understand something. Some better ways to say the same thing: I will help you understand. I will help you better understand.

I will make sure you understand it very well. or I will make sure you understand me very well. or I will help you understand it very well.

For an English speaker I would say. "I will make you understand it very well" - For future tense "I made you understand it very well" - For past tense Generally I don't use the present tense when it comes to knowledge. I wouldn't say "I teach you" "I learn you". We would user the present participle "I am making you understand very well"

i make you to understand very well

If I make you do something it suggests compulsion. I am forcing you to do something, This concept is not a natural one to use with "understand" in this way. I will make it so that you can understand it. I will make sure that you can understand it, before we move on. It seems I have explained it in a way that means you now understand very well. <-- much longer in English. English is like that sometimes.