If your English foundation is weak in junior high school, don't worry. It's not too late to improve your skills before entering high school. Here are some suggestions:

1. Review basic grammar and vocabulary: Spend time reviewing the basics of English grammar and vocabulary. You can use textbooks, online resources, or even ask your English teacher for help.

3. Read English materials: Reading English books, articles, or even comics can help you improve your reading comprehension and vocabulary.

4. Write regularly: Writing can help you solidify your knowledge of grammar and vocabulary. Try writing short essays or journal entries in English.

By following these steps, you can gradually improve your English skills and prepare for high school. Remember, consistency and practice are key to improving your English.