Dear (имя твоей подруги или друга)
How are the things going on? Did something new happen in your life? Having received your letter, I wanted to answer it immediately. But I was working a lot during the last two weeks. So I was pressed for time and did not manage to carry out my intentions.
In my country spring has already set. It is quite warm and really sunny all days long. Being at work I always imagine myself strolling down some parks. I wish you could join me! It would be funny! Some days ago my friend advised me to read a very interesting book. I did it and I would like you to know this author. Are you ready to read good litterature?
Tell me more about your work and free time. Are you satisfied with all this? What are your plans for this summer? Maybe we will be able to meet one day?
Truly yours,
(Твое имя)