A new phrase in a real context
Not a detached vocabulary item, but language connected to a moment the learner actually lived.
Research-driven adaptive AI learning technology
A new intelligence layer for human-led language learning
LingoSide listens to your live lessons, understands what you know, where you struggle and how you express yourself — then turns every conversation into personalized guidance, memory and practice. Your teacher leads the lesson. LingoSide makes every lesson compound.
Already live in the sidecar: live transcription, instant translation, AI reply suggestions — each with its translation — and live semantic RAG, so suggestions are never pulled out of thin air: when your teacher calls back to something from earlier in the lesson, the copilot gets the reference. No other app does this beside a live human lesson.*
* In our market research we found no other product that combines these beside a live human lesson — see the market review below.
Durable lesson memory, post-lesson learning and continuity across sessions.
The lesson ends. The signals should not.
Every lesson produces valuable evidence about how one person understands, speaks and recalls language. Most of it disappears when the call ends.
Not a detached vocabulary item, but language connected to a moment the learner actually lived.
The difference between what the learner intended and what they were able to say.
A construction, sound or response pattern that repeatedly slows the conversation down.
Words the learner recognizes immediately but cannot yet retrieve when speaking.
Interests, stories and situations that make future practice relevant instead of generic.
The most valuable signal — and the one a single transcript cannot reveal on its own.
From conversation to long-term learning
The intended innovation is continuity: each stage is designed to use evidence from the same real lessons, while the live experience stays quiet enough for the human conversation to remain central.
See what exists todayBefore the lesson
Long-term directionPrepare the learner to retrieve useful phrases, unresolved difficulties and relevant context before the next conversation starts.
During the lesson
Working prototypeKeep source text, translation and contextual reply suggestions in a glanceable sidecar. Finalized lesson context can be archived, and earlier moments from the same session can inform reply suggestions.
After the lesson
Archive now · review plannedThe prototype can preserve finalized session records. The next layer is intended to preserve selected phrases, teacher-confirmed corrections and evidence-linked moments for recap and practice.
Between lessons
Planned next layerRevisit selected material at useful intervals and in the context in which it first mattered, rather than generating another generic list of exercises.
The next lesson
Long-term directionUse earlier learning evidence to support better decisions for both learner and teacher — without turning the lesson into a dashboard or an automated course.
Personal learning memory
Today, when configured, the prototype can retrieve relevant earlier fragments from the ongoing lesson to inform reply suggestions, and it can preserve a session archive. Durable cross-lesson memory is the next product layer.
That memory is intended to stay evidence-backed and inspectable — not pretend to know everything about a learner.
What the learner model is designed to represent
Known and unknown constructions, active and passive vocabulary, useful chunks.
Recurring errors, hesitation points and material that has not yet become retrievable.
Topics, interests and situations that can make future practice meaningful.
What has become easier, what keeps returning and what is worth retrieving next.
Every useful memory item should remain connected to the lesson moment that supports it.
The goal is not to retain every word. It is to preserve the signals that can improve future learning.
Durable memory must be designed with clear review, deletion and retention controls before broad use.
Research-informed by design
LingoSide draws from dozens of disciplines and research areas. They are not a technology checklist; together, they define how the system should pay attention, capture and structure evidence, and decide what to bring back.
Research on forgetting, retrieval practice, spacing, consolidation and metacognition will guide how future review decides when a lesson moment should return and what effort creates durable recall.
Second-language acquisition, psycholinguistics and language pedagogy shape how input, output, corrective feedback, vocabulary and meaningful interaction work together.
Speech recognition, listening, phonetics, phonemes, pronunciation and prosody inform what could be observed responsibly in future speech analysis — and where the system should stay silent.
Knowledge tracing, adaptive learning, error classification and learning analytics offer ways to update practice from observed performance rather than a fixed course sequence.
Conversation analysis, NLP, semantic search, retrieval and generative models help structure what happened — while human-computer interaction keeps that analysis from competing with the lesson.
Research is a design constraint, not a badge. It helps decide what belongs live, what belongs after the lesson, what needs validation and what should not be built yet.
Stress-tested, not cherry-picked
No cherry-picking. We gathered the science of how people really learn languages into one brief — then tried hard to prove ourselves wrong. Only the claims that survived get to shape LingoSide.
research areas reviewed, from memory science to speech decoding
verifiable claims extracted, each tied to a published source
unique sources, with meta-analyses weighted first
feature ideas mapped from the evidence into a phased plan
Every key claim had to pass three simple tests: Is the research solid? Has it been repeated by other scientists? Does it apply to a real online lesson? Here is what happened to the 30 claims our product depends on:
Passed all three tests. We build on these.
One test raised doubts. We use them carefully, not blindly.
Popular beliefs that failed the tests. They stay out of the product.
With captions in the language you’re learning, people simply understand much more of what they hear.
In studies: g ≈ 0.99 — one of the largest effects in language research.
→ That’s why live captions are the heart of the sidecar.
Pulling a phrase from memory strengthens it far more than reading it one more time — and the gap widens over weeks.
Meta-analysis of 188 experiments: g = +0.51 vs re-reading.
→ Review will quiz you gently instead of showing lists.
Short practice spread over days wins against one long session — especially weeks later, when it actually matters.
Meta-analysis: 48 experiments, 3,411 learners, medium-to-large effect.
→ Practice lands between lessons, never inside them.
Quick hints in your native language speed up beginners — and matter less and less as you advance.
g = 0.33; the advantage shrinks with proficiency.
→ Translation appears on demand and quietly steps back as you grow.
The stronger the evidence, the bolder the feature. Solid findings become defaults, promising ones become options — and busted myths stay out, no matter how popular they are.
Under the hood
Most AI tools forget a conversation the moment it scrolls away. The LingoSide prototype is engineered around a different idea: the lesson itself becomes a live, searchable memory the AI can draw on — in real time, and later.
The core innovation
Working prototypeRAG — retrieval-augmented generation — is a fancy name for a simple idea: before the AI helps you, it first looks up what actually happened in your lesson. And “semantic” means it searches by meaning, not exact wording — you never have to remember the precise word. Say “trip”, and it finds the moment you talked about cancelling a journey. Here is how it works:
Every finished sentence from the conversation becomes a small snippet of lesson memory.
Each snippet gets a numeric “meaning fingerprint” (an embedding) and joins a live index of the lesson — organised by meaning, not just words.
When you ask for help, the sidecar retrieves the earlier moments closest in meaning and hands them to the AI — so suggestions build on your lesson, not on generic phrases.
Every AI reply suggestion is built on this memory — grounded in what was really said, not invented.
Help stays on-topic in minute 55 just like in minute 5.
The AI reads a small, relevant slice — so it stays fast and affordable.
Today this memory lives for one lesson; every session is already archived. The next layer extends the same retrieval across all your lessons — so “you met this phrase in lesson 12” becomes something the copilot can actually say.
An hour of talking is too much for any AI to re-read every time. So the sidecar keeps folding older lines into a running summary while holding the freshest lines word-for-word — the thread of the conversation survives, and responses stay quick.
A draft line appears the moment you speak and may still flicker; once the system is confident, the line freezes. Only frozen lines get translated, archived and made clickable — and each one is labelled with who said it, teacher or learner.
When the system is unsure, it stays silent instead of guessing. Speech, translation and AI providers sit behind neutral adapters, so no single vendor is load-bearing — and if a cloud service runs dry mid-lesson, that layer switches itself off gracefully instead of nagging you with errors.
For teachers, tutors and schools
LingoSide is designed to sit beside human-led teaching, not replace it. The learner remains in a real relationship with a teacher or conversation partner; the system carries forward the evidence that is difficult to track across isolated calls. That cross-lesson continuity is a planned product layer.
Discuss a future teacher or school pilotThe responsibility stays clear
Human-led by designThe product is being designed to carry continuity and analysis. The teacher keeps judgment, relationship and instruction.
A different operating model
LingoSide does not need to turn into another course, replace the human lesson or stop at a searchable transcript. It is designed to connect those lesson moments into a learning process.
| Model | Standard language app | Online lesson | Transcription tool | LingoSide |
|---|---|---|---|---|
| Primary input | Pre-built course content | A real human conversation | Audio or a call recording | Designed around real lesson audio and finalized language |
| Live role | A separate learning activity | The teacher leads and adapts | Captures what was said | Working prototype: quiet support beside the human-led lesson |
| What happens after | Continue the course path | Depends on manual notes and preparation | Search or reread the record | Archive today; planned learning layer turns selected material into future practice |
| Source of adaptation | Answers inside the app | Teacher observation and judgment | No learning model by default | Planned: observed lesson history, with the teacher still in control |
| Continuity | Inside its own curriculum | Held by the teacher and learner | A record, not a learning model | Designed to connect successive real lessons |
The LingoSide column describes the product model. Cross-lesson memory and adaptive review are in development, not presented here as generally available features.
2025–2026 market review
We reviewed the current landscape of live-caption tools, AI language tutors and marketplace add-ons, and verified each product claim against vendor documentation. A clear pattern emerged — and with it, a clear gap.
Meeting caption tools
Translated captions in video-call platforms and AI meeting notetakers stream a raw wall of parallel text or notes. There is no learning design, no dosing — and when the call ends, nothing comes back.
No pedagogy, no review, often behind business paywalls.
Marketplace AI add-ons
Tutoring platforms are adding AI summaries and practice exercises — but deliberately before and after the lesson. The live hour itself, where the richest learning evidence appears, stays untouched.
No live support, no captions, no spaced-repetition engine.
AI conversation tutors
Speaking apps offer roleplay with an AI partner instead of supporting your real tutor. Useful for extra practice — but none of them sits beside a live human lesson while it happens.
Replaces the conversation LingoSide is built to protect.
The gap LingoSide is built for
In our review, no product combined live in-lesson support with an evidence-based review loop.
Observations from our 2025–2026 competitive research, checked against vendor documentation at the time of review. Product capabilities and pricing change quickly.
An honest product horizon
The long-term vision is ambitious: a system that can observe learning evidence over months and help the learner and teacher make better decisions. The current product is an early, focused part of that system.
Clear scope, no theatre
LingoSide is at an early product stage. The live foundation is real; the durable learning system is the direction we are planning and developing for future validation.
A Windows-first working prototype exists for live lessons, with source transcription, translation, contextual reply suggestions and session archiving. The waitlist provides updates about future testing and early access; signing up does not guarantee access.
Not yet. The current system can use semantic context from the ongoing lesson and save a session record. Durable cross-lesson memory, learner evidence and adaptive review are being developed.
Those capabilities are the live foundation, not the final product category. The larger goal is to connect real lesson evidence to review, retrieval and future lessons.
Streaming speech recognition with two-phase captions (a draft that settles into a final line), speaker attribution, instant translation — and an in-session semantic memory (RAG) that lets AI help build on what was really said in the current lesson. Providers sit behind neutral adapters, so no single vendor is load-bearing. The technology section walks through it.
No. The teacher or conversation partner leads the interaction. LingoSide is designed to handle continuity and analysis while leaving judgment, relationship and instruction with the human teacher.
Primarily people learning with a teacher, tutor or conversation partner. We also welcome teachers and language schools interested in discussing future pilot use cases.
The prototype is Windows-first. Its current session configuration includes English, Polish and Russian. Android is a later direction, and language coverage will expand only as the live experience is validated.
Live lesson audio may be sent to configured cloud speech-recognition services. Transcript excerpts may also be sent to configured translation or model providers, and finalized session data can be archived. Clear consent, retention, inspection and deletion controls are requirements for the durable memory layer — not claims we make before those controls are ready.
Early access
Join the waitlist for future LingoSide testing and early-access updates. We are looking for learners who already take live lessons and care about what happens between one conversation and the next.
We’ll use this address for LingoSide testing and early-access updates. Joining does not guarantee an invitation or launch date.
For teachers and partners
If you teach online, run a language school or want to explore a learning-continuity use case, tell us about your lessons and what currently gets lost between them.
This form is for pilot conversations and partnerships. Learners can use the waitlist above.