I hope you will have a good time on Hainan Island.
When he had finished writing the letter, he read it to me.
前一个句子“我希望你能在海南岛读过一个愉快的假期”表明说话人在说话的时候对方还没有去还能拿,所以要用将来时
第二个句子,WHEN引导时间状语从句,表示当他写完信的时候马上阅读给我听。这个地方写完信在前,阅读在后,所以要用完成时。
1.1.I hope you(have) a good time on Hainan Island.
固定短语 hope sb. do sth.,用一般现在时态
2.When he finished writing the letter,he read it to me.
过去时态