Interactive tools
Free language tools
Free in-browser tools for adult language learners: drill any word list, train your Mandarin tones, build Esperanto words, and work out how long a language will take and where it would let you live.
Drill any word list
Pick a list or build your own, then play it in any game, including Flashcards and Word Drill.
Tools for one language
Mandarin
Mandarin tone trainer
Practise the four Mandarin tones on one syllable, so the tone is the only thing that changes. It drills the pairs adult learners most often mix up.
Esperanto
Esperanto Affix Sandbox
Stack mal-, -ej-, -il- and friends onto real roots and see what you have built: an attested dictionary word, or a grammatically perfect hypothetical the community can vote on.
Plan your learning
Estimator
How long does it take to learn a language?
Enter your weekly hours and target CEFR level for an estimate based on the FSI's language categories, and how far Kilo Lingo's 1,000-word certificate is at your pace.
Map
Where could I live and work?
Tick the languages you speak and a world map fills in every country where they are official or de facto national, with the share of the world's people and GDP they reach.