In the following sentence:
主要 is before a verb. In the dictionary it says it is an adjective and the uses I've seen is as an adjective like: 主要的问题, the main problem.
Can it also be an adverb? Or is it that 帮 is a noun on is own and 补习老师主要帮 is a subject+predicate, but then I don't understand the meaning of the sentence.