Could anyone kindly check the mistakes in my paragraph, please?

Hi,

However, I would like to say to you something I think is very important at least for me. I have studied English in classes in which a foreign teacher had been teaching us for two months. Although he is quite a native English speaker, we haven't benefited anything from him.

Do you know why we have understood nothing from his teaching? I would like to say to you that it hadn't been because we were stupid or hadn't a great interest in English; however, because the teacher was very keen of two things: the first is that he didn't want to bother and exhaust himself to do his job as much as he could, although his job was well paid. The other one is he didn't want to bother the students with teaching English language as it should have been taught so that they evaluate his teaching well. So he was humouring the students.

In addition, there were never any conversations between the students inside the class. However, the teacher was only teaching the unnecessary things in curriculum, which the students were able to study them with themselves. As a result, the outcome was ZERO for all students, aside from the high marks in the Exams of all students.

Finally: Something had worked for me was humor. Do you believe what that something was? "I asked my teacher someday: Why didn't you want to stretch the students in the class in order that they learn well English?" He said to me that due to difficulty English to being learnt in an environment in which English is rarely spoken. And thus, I hated every teacher like that teacher.

By the way the English language is not my specialist; however, from now on it is going to be my quite excellent great interest. And day after day it is going to be growing