使用定语从句表达“我最喜欢的电影是哈利波特”的英文句子如下：
1. "The story of Harry Potter is interesting, and my favorite movie is Harry Potter."
2. "My favorite movie is Harry Potter, because science fiction films are exciting and people find them very interesting. Especially Harry, he is a handsome and brave boy, and in the face of setbacks, he never bows. So I like the film Harry Potter."
3. "Harry Potter films are my favorites, and I find them not only entertaining but also inspiring."
这些句子都包含了定语从句，用来修饰或说明先行词"Harry Potter"。
