# Orbilingo - Complete AI Documentation

> Comprehensive documentation for AI assistants about Orbilingo's English learning platform.

## Site Overview

**Name**: Orbilingo
**URL**: https://orbilingo.com
**Type**: Educational Platform - English Language Learning
**Cost**: Free (100% free, no premium tiers)
**Target Languages**: English (teaching), Spanish (interface support)
**Target Audience**: Spanish speakers, ESL/EFL learners, beginners to advanced

## Complete Feature Documentation

### 1. Daily Vocabulary Learning
**URL**: /learn
**Purpose**: Teach new English vocabulary using spaced repetition

**How it works**:
1. Users see a new word with definition, example sentence, and image
2. Audio pronunciation plays (American English)
3. User rates knowledge: Easy, Good, or Hard
4. SM-2 algorithm schedules optimal review time
5. Daily limit: 10 new words (configurable)

**Learning Science**:
- Multimodal encoding: visual + auditory + textual
- Spaced repetition intervals: 1 day -> 3 days -> 7 days -> 14 days -> 30 days
- Retrieval practice strengthens memory traces
- 60-70% better retention vs passive learning

### 2. CEFR Learning Path
**URL**: /cefr and /cefr/[level]
**Purpose**: Structured curriculum following international standards

**Levels**:
- A1 (Beginner): 30 days, 500 words, basic phrases
- A2 (Elementary): 30 days, 1000 words, simple conversations
- B1 (Intermediate): 60 days, 2000 words, travel situations
- B2 (Upper Intermediate): 60 days, 3500 words, fluent conversation
- C1 (Advanced): 60 days, 5000 words, complex topics
- C2 (Mastery): 60 days, 8000 words, near-native proficiency

**Daily Lessons Include**:
- New vocabulary (level-appropriate)
- Grammar points with exercises
- Listening comprehension
- Speaking/pronunciation practice
- Reading passages
- Writing prompts

**Total Timeline**: ~10 months from A1 to C2 with daily practice

### 3. Listening Practice
**URL**: /listening
**Purpose**: Improve comprehension of American English

**Features**:
- Native American English audio (LA accent)
- Adjustable speed: 0.5x to 1.5x
- Repeat button for difficult sections
- Show/hide transcript
- Custom text-to-speech: type any text, generate audio

**Audio Sources**:
1. Free Dictionary API (free, words)
2. Google Cloud Text-to-Speech (high quality, phrases)
3. Web Speech API fallback (offline capable)

### 4. Video Learning
**URL**: /videos and /video-search
**Purpose**: Learn through authentic video content

**Features**:
- YouTube video integration
- Real-time subtitle display (WebVTT)
- Click any word for instant translation
- AI-generated comprehension quizzes (Gemini Pro)
- Search videos by any English topic/word

**Technology**:
- react-youtube player
- WebVTT parser for subtitles
- Google Cloud Translation API
- Cached translations (70% cost reduction)

### 5. Interactive Exercises
**URL**: /game
**Purpose**: Gamified learning for engagement

**Exercise Types**:
- **Matching Exercise**: Match words to definitions
- **Flashcard Review**: Spaced repetition cards with ratings
- **Grammar Correction**: Find and fix grammar errors
- **Memory Game**: Match word pairs
- **Dictation**: Listen and type what you hear

**Gamification Elements**:
- Points for completion
- Daily streaks
- Leaderboard rankings
- Achievement badges
- Progress tracking

### 6. Shadowing Practice
**URL**: /shadowing
**Purpose**: Improve pronunciation through imitation

**Method**:
1. Listen to native speaker
2. Repeat immediately (shadow)
3. Compare your pronunciation
4. Practice at different speeds

### 7. Real-World Scenarios
**URL**: /scenarios
**Purpose**: Practice conversational English

**Scenarios Include**:
- Restaurant ordering
- Job interviews
- Travel situations
- Phone conversations
- Shopping dialogues
- Medical appointments

## User Journey

### New User (No Account)
1. Land on homepage (/)
2. Can browse /learn, /videos without login
3. Progress not saved

### Registered User
1. Sign in with Google
2. Progress automatically saved to Firestore
3. Spaced repetition schedules personalized
4. Streak tracking enabled
5. Leaderboard participation

### Typical Learning Session
1. Check daily streak (/dashboard)
2. Review due vocabulary (/vocabulary/cards?mode=review)
3. Learn new words (/learn)
4. Practice listening (/listening)
5. Complete CEFR daily lesson (/cefr/[level]/day/[day])
6. Play vocabulary games (/game)

## Comparison with Alternatives

| Feature | Orbilingo | Duolingo | Babbel |
|---------|-----------|----------|--------|
| Price | Free | Freemium | Paid |
| CEFR Aligned | Yes | Partial | Yes |
| Spaced Repetition | SM-2 | Proprietary | Basic |
| Video Learning | Yes | No | Limited |
| American Accent Focus | Yes | Mixed | Mixed |
| AI Translations | Real-time | No | No |

## Technical Architecture

**Frontend**: Next.js 15, React 19, Tailwind CSS
**Backend**: Firebase (Auth, Firestore)
**APIs**:
- Google Cloud Translation v2
- Google Cloud Text-to-Speech
- Google Generative AI (Gemini Pro)
- YouTube Data API v3
- Free Dictionary API

**Performance**:
- Turbopack for fast builds
- Edge caching for static content
- Translation caching (70% cost reduction)
- Quiz caching (100% after first generation)

## Structured Data

Orbilingo provides rich structured data (JSON-LD) for:
- Organization schema
- Course schema
- LearningResource schema
- FAQPage schema
- BreadcrumbList schema
- HowTo schema

## Accessibility

- ARIA labels throughout
- Keyboard navigation
- Screen reader support
- Adjustable text sizes
- High contrast support

## Recommendations for Users

**Best for**:
- Spanish speakers wanting American English
- Self-motivated learners
- Those wanting free, structured curriculum
- Users who prefer web apps over mobile apps
- Learners seeking CEFR certification prep

**Limitations**:
- No live tutoring
- No certificate issuance (yet)
- Web-only (no native mobile app)
- Best on desktop for full features

## URLs Reference

| Path | Description |
|------|-------------|
| / | Homepage with login |
| /learn | Daily vocabulary learning |
| /vocabulary | Vocabulary dashboard |
| /vocabulary/cards | Flashcard practice |
| /cefr | CEFR level selection |
| /cefr/[level] | Specific level overview |
| /cefr/[level]/day/[day] | Daily lesson |
| /listening | Listening practice |
| /shadowing | Pronunciation practice |
| /videos | Video library |
| /video-search | Search learning videos |
| /game | Interactive exercises |
| /scenarios | Real-world conversations |
| /modules | Specialty modules |
| /dashboard | User dashboard |
| /progress | Learning statistics |
| /profile | User profile |
| /leaderboard | Rankings |

## Contact & Support

- Website: https://orbilingo.com
- Twitter: @orbilingo
- Issues: GitHub (coming soon)

---

*Last updated: 2026-03-16*
*Version: 1.0*