(1) sometime意为“某个时候”，可用于过去或将来：
I must go shopping sometime this morning. 今天上午我必须找时间去买东西。
Let’s have dinner together sometime next week. 下星期找个时间咱们一块吃顿饭吧。
Hopefully, I’ll see you sometime tomorrow.= I hope I’ll see you sometime tomorrow. 我希望明天什么时候能见到你。
【注】这样用的 sometime 也可写成 some time (即分开写)。
You really must come and see us some time. 你什么时候务必来看看我们呀。
(2) some time 作为副词词组，意为“任何时候”或“某个时候”(= sometime)；作为名词词组，意为“一段时间”(不能写成 sometime)：
Give me some time to consider. 给我点时间仔细考虑。
I spent some time trying to convince her. 我花了不少时间试图说服她。
The medicine took some time to kick in. 这种药需要一些时间才能生效。
For some time people had been muttering about the way she ran the department. 人们对她的管理方式私下抱怨已有时日。
(3) sometimes 意为“有时”：
Dogs sometimes produce five or six young at a birth. 狗有时一胎生五六只小狗。
The boss sometimes turns a blind eye to smoking in the office. 老板有时对在办公室抽烟假装没看见。
In summer, the temperature is sometimes forty degrees centigrade. 夏天，温度有时达40摄氏度。
Sometimes we’re busy and sometimes we’re not so busy. It all depends. 有时我们很忙，有时我们不太忙，这要看情况。
Sometimes emotional problems might lead to serious results. 有时候情绪问题会导致严重的结果。