Spanish decks for speaking out loud

The sentence deck came first, and it came from use: it already ships inside the app, and the learners who found it copied it into their own Drive and drilled it rather than moving on. That is the shape the other two follow — the answer side is always something you can say, never a single token you would look up.

The verb and noun decks are generated rather than written. Spanish conjugation and plural formation are rule-governed, so the rules live in code and only the genuine irregulars are listed by hand. Every form is then checked against a corpus of human-written Spanish, and where the corpus disagreed with the rules the deck refused to build until the entry was resolved. A deck of a few hundred cards is a few hundred chances to teach something wrong, and this is how that risk gets spent carefully.