To improve your English grades in junior high school, focus on the following aspects:

1. Vocabulary: Regularly study new words and phrases to build a strong foundation. Use flashcards or an app like Anki to memorize vocabulary effectively.

3. Reading Comprehension: Read English articles, books, or short stories to improve your reading speed and comprehension. Try to understand the context and infer meanings from context clues.

4. Listening: Listen to English audio materials, such as podcasts, songs, or movies with subtitles. This will help you understand different accents and speaking speeds.

6. Writing: Write down what you learn each day and try to use new vocabulary and grammar structures. Consider keeping a journal or writing short essays to improve your writing skills.

Remember, consistency is key. Set aside time every day to practice these skills, and before long, you'll see improvements in your English grades.