These are the patterns a beginner meets in the first months and keeps getting
wrong for a year: the particles that decide what each part of a sentence is
doing, and the handful of verb endings that carry permission, prohibition and
condition. Each lesson gives the form, what it actually claims, three worked
examples with furigana, and the patterns it is most often confused with.
Free to read, no account. They are also seeded into every Kotoba Setto deck at
no charge and never count towards the free 100 words, so you can put them on a
review schedule rather than reading them once.
Particles
The small words that say what each part of a sentence is doing. Japanese leans on them the way English leans on word order, which is why a sentence can look like a pile of nouns until the particles click.
Reading a rule once is not the same as having it. In the app these
fifteen sit in their own review pile, separate from your vocabulary, and come
back as fill-in-the-blank questions at widening intervals until they stick.