Why is comprehensible input the dominant theory of acquisition?

Because the alternatives — pure drilling, pure conversation, pure grammar study — all show diminishing returns past a certain point. Input that you mostly understand, in volume, has the strongest empirical track record.

Do I have to learn the target script before using FlixFluent?

No. Romanization is built in for Korean, Japanese, Chinese, and others. But learn the script — it pays off for years.

How does deconstruction differ from translation?

Translation gives you what a sentence means. Deconstruction gives you why it means that — particles, mood, role, dictionary form.

Is sentence mining better than passive watching?

For long-term retention of specific vocabulary, yes. For listening fluency, passive watching also matters. Most serious learners do both.

Can I use FlixFluent at A1?

You can but the value is lower — most sentences are above your level. FlixFluent shines from late A2 onwards.

Glossary of language-learning terms

This glossary collects the language-learning vocabulary FlixFluent uses across its product and documentation. Most entries are short definitions plus a one-paragraph elaboration covering the term in practice. Use it as a reference when reading the comparison or learning guides — every term linked from elsewhere on this site has its definition here.

At a glance

Definitions for the language-learning vocabulary FlixFluent uses
Cross-linked from compare, learn, and guide pages
Includes technique terms, linguistic terms, and assessment terms
Reference for FSI categories and CEFR levels

How to use this glossary

Each entry stands alone. Read top-to-bottom for orientation, or jump to a term using the table of contents below.

Terms are organised loosely from technique terms (dual subtitles, comprehensible input) to linguistic terms (particle, dictionary form) to assessment terms (FSI categories, CEFR).

Definitions

Dual subtitles

Two subtitle tracks rendered simultaneously — one in your target language, one in your base (native) language.

Used for comprehension support: the base track answers what was said, the target track shows how it was said. FlixFluent renders dual subtitles on Netflix and YouTube via the Chrome extension.

Comprehensible input

Linguistic input slightly above your current ability, where the new vocabulary or grammar is supported by enough familiar context that you can roughly understand it (Stephen Krashen, "i+1").

The core thesis: acquisition happens when you understand most of what you hear or read, with manageable surprise. FlixFluent's tools (hover translation, deconstruction) lower the threshold of comprehensibility for material that would otherwise be too hard.

Sentence mining

The practice of harvesting sentences from native content and turning them into spaced-repetition flashcards.

A typical mining loop is: encounter a sentence with one unknown word (i+1), save it as a flashcard with audio + text + translation, review with SRS over time. FlixFluent does not currently include in-product sentence mining; export to Anki is on the roadmap.

Romanization

Writing a non-Latin script in Latin letters — for example Hangugeo for 한국어, sushi for 寿司.

Romanization is a starter scaffold for learners who have not yet learned the target script. FlixFluent ships native romanization for Korean (Revised Romanisation), Japanese (wanakana / rōmaji), Chinese (pinyin via pinyin-pro), and others. Drop it as soon as you have the script.

SRS (spaced repetition system)

Software that schedules flashcard reviews based on how well you remember each card — easier cards reappear later, harder ones sooner.

Anki, JPDB, and Memrise are common SRS tools. FlixFluent does not currently embed an SRS but pairs well with one for vocabulary review outside the watching session.

Shadowing

Repeating native speech aloud immediately after hearing it, without trying to translate.

Shadowing trains the muscles of pronunciation and rhythm. FlixFluent's auto-pause + 0.5×–1× playback support shadowing without rewinding manually. Effective once you can comprehend roughly 70% of a passage at 1× speed.

Dictionary form

The base form of a word as it appears in a dictionary, before conjugation or inflection — e.g. Korean 가다 (go), Japanese 食べる (to eat), Spanish hablar (to speak).

FlixFluent's click-to-deconstruct view returns the dictionary form of any verb (or other inflected word) so you can look it up cleanly. Without it, learners often try to look up conjugated forms (갔어요, 食べました) and get nothing.

Particle

A small functional word, usually attached after a noun or verb, that marks its grammatical role — Korean 은/는, 이/가, 을/를; Japanese は, が, を, に, で.

Particles do most of the syntactic work in Korean and Japanese. FlixFluent labels each particle with its grammatical role on click, which is the single biggest comprehension win for learners of those languages.

Grammar role

The function a word or phrase plays in a sentence — subject, direct object, indirect object, location, time, instrument, modifier, etc.

In English, grammar role is mostly inferred from word order. In Korean, Japanese, German, and many other languages, role is marked by particles or case endings. FlixFluent surfaces the role explicitly.

FSI categories

A US Foreign Service Institute classification of how long it takes a native English speaker to reach professional working proficiency in a target language.

Category I (Spanish, French, Italian): ~600–750 hours. Category II (German): ~750 hours. Category III (Indonesian, Swahili): ~900 hours. Category IV (Korean, Russian, Hindi): ~1,100 hours and harder. Category V (Japanese, Chinese, Arabic, Korean (highest difficulty for English speakers)): ~2,200 hours. FlixFluent does not change these constants but reduces friction within them.

CEFR

Common European Framework of Reference, a six-level proficiency scale from A1 (beginner) to C2 (mastery).

Roughly: A1 survival phrases, A2 simple conversation, B1 daily life, B2 nuanced opinions, C1 professional, C2 native-like. FlixFluent is most useful from late A2 onwards once basic grammar is in place.

Auto-pause

A FlixFluent feature that pauses playback at the end of each subtitle line, giving you time to read, parse, or repeat.

Pairs with shadowing — pause, repeat, advance. Disable when you only want to watch.

Click-to-deconstruct

FlixFluent's feature for breaking down a clicked word or sentence into dictionary form, stem, particle, grammar role, and structural parse.

Available on every word and sentence in supported languages. Higher-leverage in morphologically rich languages (Korean, Japanese, German, Russian, Turkish).

Banmal / jondaetmal

Korean informal speech (반말) and formal speech (존댓말). The difference is socially loaded — choosing the wrong register is rude.

Watch for verb endings: -아/어 vs -아요/어요 vs -습니다/ㅂ니다. FlixFluent's deconstruction labels politeness register on every verb.

Subjunctive

A grammatical mood used to express doubt, possibility, necessity, emotion, or hypothetical situations — strong in Spanish, French, Portuguese, less so in English.

FlixFluent labels mood (indicative / subjunctive / conditional) on click for romance languages, making subjunctive triggers visible in real sentences.

Case (Nom / Akk / Dat / Gen)

A morphological marking on a noun phrase indicating its grammatical role — German Nominativ (subject), Akkusativ (direct object), Dativ (indirect object), Genitiv (possessive).

Languages with case (German, Russian, Latin, Finnish) require explicit role tracking. FlixFluent labels case on every clicked noun phrase in supported languages.

Frequently asked questions

Why is comprehensible input the dominant theory of acquisition?: Because the alternatives — pure drilling, pure conversation, pure grammar study — all show diminishing returns past a certain point. Input that you mostly understand, in volume, has the strongest empirical track record.
Do I have to learn the target script before using FlixFluent?: No. Romanization is built in for Korean, Japanese, Chinese, and others. But learn the script — it pays off for years.
How does deconstruction differ from translation?: Translation gives you what a sentence means. Deconstruction gives you why it means that — particles, mood, role, dictionary form.
Is sentence mining better than passive watching?: For long-term retention of specific vocabulary, yes. For listening fluency, passive watching also matters. Most serious learners do both.
Can I use FlixFluent at A1?: You can but the value is lower — most sentences are above your level. FlixFluent shines from late A2 onwards.

Sources & further reading

Install FlixFluent

Add FlixFluent to Chrome and turn Netflix or YouTube into an interactive language lesson. 7-day free trial, 30-day money-back guarantee.

Install from Chrome Web Store