I'll come round sometime around eight. Sometimes I find it really difficult to get out of bed. I need some time to think about it. Some times would work in English, strictly speaking, but I can't think of an example sentence that doesn't sound contrived. I don't think you need to worry about it.

sometime = adv. a time that you don't know exactly 将来某个时间. e.g. We must have breakfast together sometime. sometimes = adv occasionally 常常 some time = a short period of time 离现在不远的过去. e.g some time ago we spoke about this 希望我能够说清楚。加油！

1. Sometimes This is an adverb meaning 'occasionally' or 'from time to time'. For example, 'I usually have tea with my breakfast, but I sometimes have coffee'. 2. Some time This refers to one unspecified occasion, usually in the future. For example, 'I'll call you some time next week'. Some people run these together as one word ('sometime') but this is not necessary. In fact, running these two words together serves no grammatical purpose. We'd say 'some day next week' or 'some morning next week' as two separate words, so it there is no logical reason to make 'some' and 'time' one word. It seems pointless and confusing. It's much more straightforward to say 'some time'. 3. Sometime The only time it is necessary to put 'some' and 'time' together as one word is when it is an adjective. For example, 'He's an actor, a singer and a sometime poet'. This is unusual, though. If I were you, I'd forget about the word 'sometime'. 4. Some times This means 'certain occasions'. For example, 'There are some times in our lives when we have to make difficult decisions.' I hope all that's clear for you now.