How do you learn all the complicated bits of “My homework was eaten by my dog”? Simple: Use the explanations and translations in your grammar book to understand what a sentence means, and then use flashcards to memorize that sentence’s component parts, like this:
Suggests making flashcards for each of the three types of changes, in any given example. allows speeding up compared to the book, as you do them w visuals on flash cards, and the spaced rep takes out most examples in a grammar book, leaving you with the repetition you need only.