To become fluent in English, continuous learning and practice are essential. Below are several methods to improve your English proficiency in 21 days:

1. Dedicate time daily to learning English: Spend at least 30 minutes to 1 hour each day studying English. Focus not only on grammar and vocabulary but also on practicing listening and speaking skills.

2. Practice listening: Listening to native speakers of English helps you learn rhythm and intonation. Utilize movies, dramas, music, podcasts, etc., to enhance your listening skills.

3. Practice speaking: Actively engage in speaking English by practicing speaking exercises. For example, introduce yourself in English, imagine conversational situations, and speak as if in real conversations.

4. Use flashcards to memorize vocabulary: Flashcards are effective for vocabulary memorization. Create your own or use online apps and sites to efficiently learn new words.

5. Study grammar: Learning basic grammar rules and understanding sentence structures are foundational for speaking fluent English. Use grammar books or online learning materials to study grammar.

6. Actively participate in English communication: Join English conversation groups or online English services to increase opportunities for real conversations. Communicating with others in English allows you to learn natural expressions.

By consistently following these methods for 21 days, you can improve your fluency and everyday conversation skills in English. Good luck!