Mark wants to know how I am settling in to the new house/ if I can visit to help him in the summer
Gross/ it is not the best hobby you can imagine
P1 - thank for the letter and apologize for not writing
P2 - description of a typical day
P3 - invitation/ giving news
P4 - finishing and asking for reply
I had better close now = I must go (both informal)
Thanks a lot for the letter = Many thanks for your last letter ( both informal)
Yours sincerely - Best wishes
By the way - that reminds me - informal
All the best - best wishes - informal
I would be most grateful if you could inform me - FORMAL - let me know
I look forward to your prompt reply - can't wait to hear from you
Please write and tell me - let me know
B - informal
I'm looking forward to hearing from you
I'm, it's, haven't
Informal letter
LINKING WORDS
But, while, so, and, as well, as