studyhiragana.com/grammar
Beginner grammar lessons covering the core patterns from the copula through relative clauses, with interactive drills for each topic. Teaches plain forms first, sequenced so each lesson builds on the previous ones.
GrammarCourses, textbooks and schoolsJLPT N5ParticlesVerb conjugationAdjectivesCasual speechHiraganaBeginnerTransitive and intransitive