[Grammar] correction of grammatical errors

[kimosu]

Hello,
I want to know the grammatical error in the following recommendation letter.

Dear Sir/Madam,
This recommendation letter is for Mr. Kishore Kumar Akula. I know him since 2002. I taught him Educational Psychology during his B.Ed. He has many times shown high caliber than a normal B.Ed student because of his mathematical and computer science knowledge. He was one of the top rankers in B.Ed entrance examination conducted state wide in Andhra Pradesh. He actively participated in various workshops such as providing awareness of AIDS etc., for rural people.
He has amazing ideas and theories related the educational psychology & learning process for special education students. If he can prove those theories, it would be quite useful for the future generations. As his teacher and as an individual I closely observed him, I give him the top priority for either his admission into higher studies or for his career.

Sincerely