Dear Mark,
Thank you for your letter. You asked me for some advise about swimming.
In my opinion it's necessary to be able to swim. It's a must. Well, it's all right to start swimming at your age. I don't think that it's difficult to learn to swim, so you won't need to have a lot of swimming lessons! So I only wish you success! And what about doing some other sports? Do you like, for example, jogging?
Or can you play volleyball? What is your favourite kind of sport?
That's all for now. Well, I'd better go now as my mum's calling me for dinner.
Keep in touch.
Best wishes,
Alex