Sometimes

sometimes, sometime, some time

这三者的区别是：sometimes的意思是“有时,间或”,指某事在某些场合会发生,并非在一切场合都发生; sometime指过去或将来的某一未知时间或某一尚未确定的时间点; some time则是名词短语,指时间段,意思是“一些时间”“某个时段”。例如:
People held in high repute are sometimes quite ignorant.名气大的人有时却非常无知。
Let's have dinner together sometime next week.下周找个时间我们一起吃顿饭吧。
I'll be away for some time.我要离开一段时间。

sometimes, always, often, usually

这四个词意思相近。它们的区别是：
1.表示的频率不同。例如：
He comes to school on Monday,Tuesday,Wednesday,Thursday,Friday,Saturday and even on Sunday.我们可说：He always goes to school.always表示的频率是100%。
He comes to school on Monday,Tuesday,Wednesday,Thursday and Friday.我们可说：He usually goes to school.usually表示的频率是90%。
He comes to school on Monday,Tuesday,Wednesday and Thursday.我们可说：He often goes to school.often表示的频率是60%。
He comes to school on Monday and Thursday.我们可以说He sometimes goes to school.sometimes表示的频率是20%。
2.always的反义词是never; often的反义词是seldom; usually的反义词是occasionally, sometimes的反义词是always。

sometimes，sometime，some time

这一组词都是与时间相关的副词。
sometimes是个频度副词，意为“有时”，表示动作发生的不经常性，常与一般现在时或一般过去时连用。
sometime是个副词，意为“某时”，指时间上不确定的某一点，常用于过去时或将来时。
some time是个名词短语，意思是“一段时间”，在句中常与for，take等词连用。