Good evening ladies and gentlemen!
Could you please tell me where the difference between "to agree with" and "to agree on" is?

Thank you very much!
AnonymousSo it doesn't matter which one I use?
It does matter. You usually agree on a matter with a person :
I agreed on the price with the vendor.

Let's agree on the issue.
I agree with the issue.
Let's agree with each other.
I agree with you.
Students: Are you brave enough to let our tutors analyse your pronunciation?
So it doesn't matter which one I use?
 Cool Breeze's reply was promoted to an answer.