玛丽一个小时前去看电影了的英文
玛丽一个小时前去看电影了。
An hour ago, Mary went to watch a movie.
Mary went to see a movie one hour ago.
An hour ago, Mary went to the cinema.
Mary went to watch a film an hour ago.
以上是几种表达玛丽一个小时前去看电影了的英语句子，可以根据具体情境和口语习惯进行选择。