Built on how memory works

New learners choose “I'm a total beginner” and start at level 1, or take a 3-minute level check: about 40 words, one at a time, each with a simple question: do you know this word?

About 10 of them are made up. They look Spanish but aren't words, and saying yes to them lowers your score. That corrects for overclaiming, so the check works without any typing. The method is LexTALE-Esp, a test used in language research. Items start spread across all levels and narrow toward where your answers change.

Words well below your level aren't taught again. They come up once as a harder question; get it right and the word is marked as known.

Words are ordered by how often Spanish speakers actually use them. Each level is 500 words: level 1 is the 500 most common, level 2 the next 500, and so on, with no top. Common words with several meanings are taught one meaning at a time, starting with the most common.

1. 1

   The word page

   The meaning in English and a short definition, example sentences with audio, related words, and for some concrete words a picture. A memory hook appears only when there's a good one.
2. 2

   Got it, or I already know this

   Got it leads straight to an easy question. I already know this jumps to a harder one: get it right and the word is scheduled as known, get it wrong and you just see the page again. Trying never costs you anything.
3. 3

   A second check

   Four to six questions later, the word comes back in a different form, before it has time to slip away.

For words you can probably work out, like ones that look like English, you guess the meaning first and then see the word page. Guessing first makes the word stick better, and the guess never counts against you.

Every word you study has a memory model behind it. LenguaLearn uses FSRS, an open-source scheduler and one of the most accurate available. After each answer it estimates how likely you are to remember the word on any later day, and the word comes back when that chance falls to about 90%: right before you would forget it.

The next item is always the most useful one: a word you just missed, a new word's second check, the review you're most likely to forget, or a new word. You're never left with nothing to do.

Reviewing a word three times in one session isn't treated as three days of practice. Repeats within a day are modeled as short-term memory, so the schedule stays honest.

Understanding a word when you see it and producing it yourself are different skills. LenguaLearn tracks them separately: a recognition memory and a production memory. Production practice starts once you recognize the word reliably (after about three days of stability), and each question only updates the memory it tests.

The kind of question depends on how well you know the word. The type also changes from one review to the next, so you never get the same type twice in a row for a word.

New, or under 2 days

Recognize it: see the Spanish word and pick its meaning from four options, or hear it and pick the meaning.

2 to 10 days

Choose it: pick the Spanish word for an English meaning, fill a gap in a sentence, match a synonym or opposite, or pick a noun's gender.

Over 10 days

Produce it: type the word from its meaning, type the missing word in a sentence, spot the sentence that uses it correctly, or type a word you hear.

Wrong options are chosen to be believable but never also correct: never a synonym or a word that's easy to confuse with the answer. Every question has an I don't know button, which is better than guessing and never counts as a mistake against your attention.

Typed answers are judged kindly at first and more strictly as a word gets stronger. The correct spelling is always shown, and the right word in the wrong form is marked as such, with the right form next to it.

New words keep coming only while you're keeping up. Otherwise the session focuses on review until you catch up. Learning more words than you can keep is the most common way vocabulary study fails.

A word counts as learned when you've recognized it after a gap of at least 7 days and the model still predicts at least an 85% chance you remember it. Your home page also estimates your whole vocabulary, including words you knew before you started.

Time counts only while a question or its feedback is on screen and the tab is visible. After two minutes without input the session pauses. Stretches that look like random clicking are counted separately as flagged time, with one gentle note to slow down. More in for teachers.