sometimes=at times,有时候,偶尔的意思 Sometimes I work in the day and sometimes at night.
sometime表示(过去或将来的）某一时刻 I hope to go to Beijing sometime soon.
some times的time当次数讲,表示几次 My uncle has been to London some times.
some time 一段时间 It takes some time to cultivate some friendship.
答案为sometime