口语和书面上都只有 keep doing sth,其他两个是错的.stay在这种短语里面不能替换keep,不过有stay to do sth,但是表达的不是“依然做什么”而是“留下来做什么.”
譬如,Please keep writing him letters.Please stay to write him a letter.加勒比海盗4我还没看,不过staying she goes应该不是正规英语,海盗语很多都是不符合语法的.