1. Sometimes is an adverb of frequency. Think of it as halfway between never and always.
Sometimes I am so tired I can’t get out of bed!
He sometimes plays tennis instead of going to the gym.
We like to go to the beach on vacation sometimes.
2. Sometime (no ‘s’) is also an adverb, but it is used to talk about an unspecified point in the future or an unspecified point in the past.
We should get together for coffee sometime!
Sometime soon I would like you to clean your room!
The accident occurred sometime before 6pm.
3. When you use some time, it’s like saying ‘some food’ or ‘some people’ – some is used to talk about how much of the noun time you have or want.
Do you have some time to check my essay?
She has some time to spend in her garden now that she has quit her job.
Take some time to think about the offer before you accept or decline it.
He was able to buy some time by saying his wife was out of town & he can’t make a decision without her.
(idiom: to buy time = to get more time; he wanted more time to make a decision so he said he couldn’t make a decision without his wife.)
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Vocabulary: Everyday or every day?.