To self-study high school English knowledge in junior high, you can follow these steps:

1. **Build a Foundation**: Review your junior high English vocabulary and grammar to ensure a strong foundation for advanced concepts.

3. **Practice Reading**: Read high school-level English texts, including novels, essays, and articles to improve comprehension and critical thinking skills.

4. **Enhance Writing Skills**: Write essays, summaries, and responses to texts to practice expressing yourself clearly and effectively in English.

6. **Use Resources**: Utilize online resources, educational apps, and study guides designed for high school students to supplement your learning.

7. **Set Goals and Practice Regularly**: Create a study plan with specific goals, such as reading a certain number of pages per week or completing a writing assignment each month. Stick to your plan and practice consistently to see improvement over time.