Dear Mike,
How is everything with you ? I feel really happy to receive your English dictionary as my birthday present. Thank you very much. As you know, I am not good at English. Sometimes I find it really hard to follow my teacher in class, so I often get low grades in English exams. So this dictionary is really good for me to learn English. And I will make full use of it to improve my English. I really look forward to hear from you.
Yours
xxx