Cognate Measures the Words You Actually Retain

Field notes

The vocabulary estimate uses a binary-search-like sequence over frequency-ranked word lists: the page shows Spanish narrowing from 20,303 to approximately 2,400 words in sixteen answers. Study then treats each word as a review item, with FSRS-6 scheduling and a 90% retention threshold. Cognate says its language lines are built from open sources by Tanzi Labs, downloaded once for offline use, and organized across 49 languages, including Armenian, Ancient Greek, Esperanto, Latin, and Welsh.