Based on Krashen's i+1 Hypothesis

Master English through
Comprehensible Input

Read EPUB books with intelligent vocabulary filtering. Only see annotations for words beyond your level. Let context do the teaching.

The old man sat alone in his study, surrounded by towers of dusty布满灰尘的 books. He had spent a lifetime accumulating积累 knowledge, yet felt overwhelmed不知所措 by how much remained unknown.

"Wisdom," he murmured低声说, "is not about knowing everything. It's about understanding what truly matters."

98%+
Fluent Zone
1 unknown per 50 words. Learn from context.
90-98%
Learning Zone
AI scaffolding recommended.
<90%
Challenge Zone
Consider easier material first.

The 98% Rule

Linguist Paul Nation's research shows that 98% vocabulary coverage is the threshold for fluent reading.

LinguistReader analyzes every book's vocabulary against your CEFR level (A1-C2). Before you open a book, you'll know if it's in your optimal learning zone.

Designed for Deep Learning

Every feature is grounded in language acquisition research.

CEFR Vocabulary Filter

Set your level (A1-C2). Only words above your level get annotated. Reduces cognitive load; keeps reading flow intact.

Smart Lemmatization

"runs", "running", "ran" → run. Word book tracks lemmas, not surface forms. Your true vocabulary, measured accurately.

Bilingual Mode

Paragraph translations with sentence-level alignment. Hover on translation to highlight source. Scaffolding, not crutch.

Context-Aware AI

"Get" has 20+ meanings. Our AI explains this specific usage in this sentence. No dictionary noise.

Contextual Word Book

Save words with their original sentence + surrounding context. Jump back to source location anytime. Context-dependent memory.

Anki Export

One-click export to Anki (.apkg). Cards include source sentence and context. Spaced repetition with real reading memories.

BYOK: Bring Your Own Key

Language Sandwich Method

Our AI prompts are engineered with a three-layer strategy:

  • 1Instructions in English — precise reasoning
  • 2Explanations in your native language — clear understanding
  • 3Examples in target language — immersive learning

Supports OpenAI, Anthropic, Google, DeepSeek, Groq, OpenRouter, and any OpenAI-compatible API.

What does "get" mean in "I finally get it"?
AI
Contextual Meaning

In this sentence, "get" means to understand.

This is an informal usage. The speaker suddenly understands something after being confused.

Local-First Philosophy

Your learning data is your digital asset. No cloud accounts. No subscriptions. No data mining.

SQLite Database

All data stored locally in an open format. Full offline access. Your files, your control.

BYOK Model

Bring your own API keys. Direct connection to AI providers. No middleman, no markup.

Total Export

Export to Anki, CSV, or full backup. Your knowledge graph goes wherever you go.

Three Zen Themes

Inspired by Japanese aesthetics. Ma (間), Kanso (簡素), Seijaku (静寂).

Hakuji / 白磁

The clarity of white porcelain.

Light Theme
Genbu / 玄武

The depth of the Black Tortoise.

Dark Theme
Washi / 和纸

The warmth of traditional paper.

Paper Theme

Read Deeply. Think Clearly.

Available for macOS, Windows, and Linux. Free forever.