DuoNinja

DuoNinja brings together your language setup, lessons, reading, vocabulary, and flashcard decks in one app.

Need help, found a bug, or have an idea? Use the Feedback button on this page or in the app menu.

How things fit together

Your language course is the main container for one learning setup.
Lessons are structured lesson tracks you open from the Lessons tab. When you finish a lesson session, words from the phrases you studied can be tracked as Seen in Vocabulary.
Reading can track words as Seen when you mark a text as read or move to the next page in books.
Vocabulary stores words and meanings for one language course.
Decks are for flashcard practice. A word and its meaning can be linked to one or more decks.
Study reviews deck cards with spaced repetition. If the same meaning appears in multiple decks, review progress follows that shared meaning.

Your language course and lessons

Your language course is your main learning setup, such as Spanish from English. It controls your decks, reading, Vocabulary, daily goal, streak, and default language preferences.

You can have more than one language course and switch between them. A course can also have a regional variant, such as Brazilian Portuguese vs European Portuguese, so reading, spelling, phrasing, and audio better match what you want to learn.

Lessons are structured learning paths with units, phrases, and exercises. They are separate from your language course setup.

When you finish a lesson session, DuoNinja adds words from the lesson phrases to your Vocabulary as Seen. Keywords from the lesson word list also get a Seen translation when the lesson provides one. Lesson review (practicing phrases you already studied) does not add new words to Vocabulary.

Vocabulary is also filled through reading, decks, and meanings you save yourself.

Daily streak

Your streak shows daily consistency. It counts at most once per calendar day in your timezone.

You can keep your streak by completing any one of these activities:

Lessons - complete a lesson.
Flashcards - complete a flashcards session.
Reading - read at least 200 words in a day.
Listening - listen for at least 5 counted minutes in a day.

Reading counts newly read words. Listening counts when the audio plays, including when you listen to the same text again.

Streaks are per user, not per language. It does not matter which language you study, as long as you complete one qualifying activity that day.

Reading

Read articles and books matched to your active language course. When you mark a text as read, or move to the next page in books, DuoNinja can track words from that text or page as Seen in Vocabulary.

If you tap a word and save a meaning, that meaning is saved to Vocabulary. In articles, you can also select a short phrase and save a meaning for the whole phrase. Neither action automatically turns every word into a flashcard.

Vocabulary

Your Vocabulary belongs to one language course. It shows words DuoNinja has seen and meanings you have saved.

Word - the word or phrase in the language you're learning.
Meaning - the translation or explanation for that word.
Saved - you chose to save a meaning to your Vocabulary.
Synonyms - different words that share the same saved or seen meaning.
Seen with meaning - the word has at least one translation from reading, lessons, or decks that you have not saved yet.
Seen without meaning - the word is listed, but it has no translation yet.
Seen words - every word DuoNinja has tracked in your Vocabulary, with or without a meaning.
In deck - that saved meaning is linked to one or more flashcard decks for Study.

A saved meaning is shared across the app. If it appears in more than one deck, editing it or reviewing it updates the same meaning everywhere.

Deleting a word removes it and its meanings from Vocabulary. Reading will not add that word back automatically when you see it again, but you can add it again manually by saving it from lookup or by adding/importing it through decks.

You can filter Vocabulary by source, including Lessons, to see words first noticed while studying a lesson course.

Decks, Vocabulary, and Study

Under Vocabulary you manage your decks. Decks are public by default, but you can make them private when you don't want to share them.

You can add cards by hand, paste a bulk list, import from Duolingo with the browser extension, or copy public decks from Community when the languages match.

There are two types of decks - flashcard decks and generated drills decks.

Flashcard decks preserve the word form and meaning of the word you added to the deck.

Generated drills decks are for practicing specific forms of the words. When you add an existing word, AI will autogenerate a specific form based on your instructions and add those words as seen words (along with the meanings) to your vocabulary. When you add cards manually to the deck from scratch, their form will be left intact - AI does not generate anything extra in that case.

Decks use spaced repetition system (SRS).

Deck progress states

Deck progress shows how far your deck has moved from new material toward stable memory.

New - cards you have not studied yet.
Learning - cards you have started studying, but DuoNinja still brings them back frequently.
Reviewing - cards that are being spaced out over time.
Learned - cards you have remembered across longer gaps.

Learned cards can still come back for review later. It means they are stable enough to count as progress, not that they are gone forever.

Audio

Your language course can have a default voice for the language you're learning. That voice is used across the app when nothing more specific is set.

Lesson courses and flashcard decks can choose their own voices. When they do, that more specific voice is used instead of the language course default.

AI actions and credits

Some helpful actions use AI, such as generating example sentences, translating sentences, translating selected words, or creating images. These actions use credits. Premium gives higher limits.

Duolingo import and browser extension

The DuoNinja browser extension can import Duolingo vocabulary into a deck so you can practice it here alongside your trees.

Feedback

Questions, bugs, and ideas all go through the feedback form. Use the Feedback button on this page or in the app menu.