Learning a Language Using Only Words You Know
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A proof-of-concept language learning app that uses LLMs to generate definitions of unknown words using only previously mastered vocabulary.
HN · launched Dec 15, 2025 · 84 upvotes (top 12%) · 0 views
Niche: language learning apps · 511 launches, 50 in the last 7 days ▼ -6% · Explore this niche →
Category and tags
- Education
- Content generation
- B2C
- Not AI
- Hobby / open-source project
Visit website ↗ Source listing ↗
More like this: all 511 launches in language learning apps →
Could you build this?
Yes This is a prompt-engineering and validation application that compares LLM output against a set of known user words using standard tokenizers or dictionary lookups.
Discussion
20 comments analyzed.
Competitors mentioned: Anki (flashcard SRS), Dreaming Spanish (comprehensible input), Language Transfer (grammar-focused courses), Koucai.chat (AI Mandarin penpals), Lingoku.ai (vocabulary expansion through reading)
Concerns raised: Generated explanations may be inaccurate or imprecise compared to dictionary definitions, Mobile experience is poor; can't upload full text files, Grammar issues with measure words and other language-specific structures, Requires manual setup of known vocabulary lists, Better suited for intermediate learners; less effective for advanced learners seeking fluency
Feature requests: Inverse product: replace ~95% of text with learner's known words, leave ~5% in English/native language, Prepared/example texts available to start reading immediately, Support for more advanced model with better context awareness (e.g., Gemini 2.5 Flash Lite), Regeneration loop for comprehensible input (N+1 approach), Add new languages beyond current offerings
Competitors
Other products that read as similar to this one : 818 launches clear the similarity bar, closest 8 shown.
Attention rank: #97 of 819 (itself plus its competitors, highest first, normalized so YC and Product Hunt are compared fairly).
Launched 47 days after the earliest competitor.
- Language Model Builder (an app to learn about and build models) · hn · 2026-07-21 · 17 upvotes · similarity 0.55
- Llm-language-learning · github · 2026-09-14 · 14 upvotes · similarity 0.54
- studyweave · github · 2026-10-26 · 15 upvotes · similarity 0.54
- AI英语口语练习 · ph · 2026-11-06 · 1 upvotes · similarity 0.51
- KillSwitch · hn · 2026-09-19 · 10 upvotes · similarity 0.50
- Learn English & Vocabulary AI · ph · 2026-10-23 · 1 upvotes · similarity 0.50
- watching · github · 2026-10-16 · 57 upvotes · similarity 0.50
- Vocab Top · hn · 2026-08-05 · 18 upvotes · similarity 0.49
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