To transition from junior high English to senior high English, it's essential to build a strong foundation in vocabulary, grammar, and reading comprehension. Start by expanding your vocabulary through flashcards or word games. Practice using new words in sentences to solidify their meanings and applications.

Next, focus on mastering the fundamentals of English grammar. Review verb tenses, sentence structures, and punctuation rules. Consider using online resources or tutoring services to address any areas of weakness.

In addition, practice writing essays, summaries, and responses to enhance your critical thinking and communication skills. Don't forget to proofread your work to catch errors and refine your writing style.

Finally, engage with English by speaking and listening as much as possible. Join language exchange groups, participate in debates, or watch English-language movies to immerse yourself in the language and improve your pronunciation and listening comprehension.