"English File" (Oxford University Press): A widely-used series in language schools. Find learning resources on the official site. https://elt.oup.com/student/englishfile/
"Headway" (Oxford University Press): Another popular and effective textbook series.
Online Courses & Apps:
Duolingo & Memrise: Great for building foundational vocabulary and grammar in a gamified format.
Write essays, join online forums, or start a blog in English. Use tools like Grammarly or ProWritingAid to refine your writing.
Exam Preparation:
Cambridge English Exams (C1 Advanced & C2 Proficiency): These are globally recognized exams for higher-level proficiency. You can find free practice materials on their official website. https://www.cambridgeenglish.org/exams-and-tests/
IELTS & TOEFL: If you plan to study or work abroad, these are the most common exams. Both have extensive free resources on their official websites.