Final answer:
An email to a friend declining an invitation to a summer house due to prior academic commitments but expressing sincere thanks and hoping for a future visit.
Step-by-step explanation:
Dear Ahmed,
Thank you so much for the generous invitation to join you and your family for two weeks at your new summer house on the coast. This kind of offer is something that is deeply appreciated, and it's wonderful to have such thoughtful friends. The idea of spending time by the sea, enjoying the company, and making new memories is incredibly tempting.
Unfortunately, I must explain that I am unable to join you this time. I've recently committed to a summer course to prepare for university, which has a strict attendance policy. My academic goals have to take priority, and I cannot miss the classes. However, I would love to see photos and hear about your coastal adventures. Perhaps we can arrange a weekend visit later in the summer when my schedule is more flexible.
Please extend my thanks to your family for their kindness, and I hope you all have a fabulous time. Take plenty of pictures, enjoy every sunset, and build amazing sandcastles for me!
Best regards,
Bob