I have recently enrolled in an elective course from our degree program. There is something that sometimes annoys me, namely the English used by the professor.
He is not a native English speaker, but it is not about his accent or pronunciation. These are decent. The problem is that he keeps applying the grammar rules of his native language to English. Sometimes, things he said in lectures were logically (sometimes, mathematically) nonsensical to everyone. The meaning of what he said was not always what he intended to convey (from a mathematical perspective).
That is also the type of English that we will see in the final exam. I have seen some past exam papers, and there is an inconsistency between the written requirements (in English) and his proposed solutions (mathematical translation of the requirements).
Normally, it is not a big deal for me. However, I occasionally gave him some suggestions in a very polite way instead of accusing him of using incorrect grammar, so it will be easier for students to understand during the lectures (and also during the exam). He always responded with something like "well, it is natural to use this in real life" and suggested that I should familiarize myself with his English instead. It disappointed me.
I want to take the matter further in a polite way (is it even a wise thing to do?). What should I do in this situation?
PS: I feel bad for asking this question as I quite enjoy his lectures
Update: We have reached a temporary solution with the professor. We will try to learn his English (through past exams), but he will also need to explain his "terminology" in detail. During the exam, we can ask him questions if there is anything ambiguous. It is something that we have to deal with.