Pick a language pair. Each one is its own self-contained 100-day curriculum:
you memorize 5 phrases a day, the narrative under each phrase quietly installs
one underlying pattern of the language.
Add a new pair? See es/AUTHORING.md for the recipe
(or open the file directly: idiomas/es/AUTHORING.md). To register a
new pair on this page, append an entry to the PAIRS array at the
bottom of idiomas/index.html.