I often hear Chinese middle school students complaining about learning grammar. In the background of exam-oriented education in Chinese Mainland, grammar is usually considered as a tool for exams, which has little use in daily life.

That is a misunderstanding of grammar. Grammar should not be that useless. Contrarily, it is a useful tool helping us to learn good English by guiding us to speak and write well. For English learners, grammar is a must that we all should learn.