Dear Luca ,
I'm glad you can come to England this summer, and my sister is pleased, too.
Of course you can stay at our place. We've got a spare room for guests.
You see, our flat isn't exactly chic, bur it's quite big. When can you come ?
Marta has got a car now, so we meet you at the airport.
Phone me when you're got an exact date.
See you soon,