some time, sometime and sometimes

Some time (with two stresses: /ˌsʌm ˈtaɪm/) means ‘quite a long time’.

• I’m afraid it’ll take some time to repair your car.
• She’s lived in Italy for some time, so she speaks Italian quite well.

Sometime (/ˈsʌmtaɪm/ refers to an indefinite time, usually in the future. It can also be written as two words: some time.

• Let’s have dinner together sometime next week.
• When will I get married – this year, next year, sometime, never?

Sometimes (/ˈsʌmtaɪmz/) is an adverb of frequency (see here). It means ‘on some occasions’, ‘more than once’ (past, present or future).

• I sometimes went skiing when I lived in Germany.
• Sometimes, in the long winter evenings, I just sit and think about life.

note

For sometimes and once, (see here)