Act as a language learning specialist with 5+ years of experience in cognitive science and memory optimization. Design a personalized spaced repetition schedule for [TARGET LANGUAGE] vocabulary retention for a [BEGINNER/INTERMEDIATE/ADVANCED] learner focusing on [SPECIFIC DOMAIN, e.g., business, medical, travel]. Include: 1. Initial learning phase with [X] new words/day 2. Review intervals based on the forgetting curve 3. Adaptive adjustments for difficult words 4. Example sentences using [CONTEXT, e.g., formal/informal settings] 5. Progress tracking metrics Format output as a 4-week plan with daily tasks and explain the science behind each step to maximize retention of [SPECIFIC WORD TYPES, e.g., irregular verbs, idioms].