I agree with you, that grammar is an important point in language learning. I am currently teaching myself and I see most textbooks do not really focus on grammar. When I studied Japanese, most textbooks gave structures, but did not explain why something is like it is. When I later studied Japanese at university the focus lied only on grammar. The first time I really understood why Japanese functions in the way it does (why is taka.kat.ta an adjective, but grammatically it behaves like a verb etc...). In everyday language learning this would go to deep and confuse the learner. But vocabulary and grammar are the most important things a beginner should try to manage. Thanks for your article on the Japanese tenses.

Thank you Rudravarman san! I hope the artcile helped you somehow.