rigorous, strict
El control de calidad aquí es muy riguroso.
Quality control here is very rigorous.
Memory lets a word go along a curve. Spaced repetition puts the next review just before the word slips, so every repeat buys more time than the one before it.
Seven cases, no shared vocabulary and a stress mark nobody writes down. What is genuinely hard about Lithuanian for an English speaker, what is easier than advertised, and the order that works.
Verba sends a short dictation every morning and brings the word back exactly when it starts to fade.
