1 sometime,some time与sometimes三个都可以表示时间.它们看起来没多大区别,但用法却各不相同.
sometimes用作副词,表示“有的时候”,与from time to time 意思相同,可以把它放在句首,句尾或句中.sometimes是频率副词,它暗指某动作（在过去、现在或将来）有时候重复.如：
Last year she went to the park sometimes.
Sometimes I get up at six.
I sometimes think you are wrong.
2 sometime 用作副词.表示某个不确切或不具体的时间,表示“某个时候”,它后面应该接一个过去或将来的时间.例如：
Tom went back home sometime last month.
We will have a meeting sometime next week.(sometime last year,sometime next month等常修饰非延续性的谓语)
另外,sometime还可以用作形容词,表示“以前的”,如：
A sometime student of yours is waiting for you at the gate.
3 some time 表示"一些时间"或“一段时间”,可以用作名词或副词短语.例如：
She always spends some time on her English.
It took us some time to water the flowers.
some time表"某一段时间"时,常常修饰延续性的谓语.如：
She stayed in bed for some time.
I will work in Japan for some time.
4.some times 是名词词组,意为“几次,几倍”,如：
I met him some times in the street last month.
The factory is some times larger than that one.