Hello, 其實無論係咪return都係，Google過下copy & paste啲覺得唔錯嘅point過嚟，其實都係不外乎三大element：

1. Show Your Appreciation: “Thank you so much for the offer for XXX position. I so appreciate you taking the time to consider me and for answering so many of my questions about the company and role.” (如果係return的話，仲可以mention少少internship時嘅教導)

2. Give a Good, Brief Reason: “After careful consideration, I’ve decided to accept a position at another company.”

3. Stay in Touch: “It’s been a pleasure getting to know you, and I hope that we cross paths in the future.” -> 最後都留一手，始終宜家唔join公司，但難保日後仲會有其他機會，或負責嘅同事都轉工去你將來嘅公司度做。