Dear [Friend's Name],
Thank you for your letter! I’ve been studying English for several years now, and while I feel confident in many areas, grammar still presents some challenges for me too. I often find exceptions to rules quite confusing. Besides English, I'm also learning Spanish, which has been both exciting and difficult. Vocabulary can be tricky sometimes, especially with all the new words I encounter. How about you? I'd love to hear more about your experiences with English and any other languages you’re studying!
Best wishes,
[Your Name]