Former; sometime.
In plain English: Sometimes means happening only occasionally and not all the time.
"The job sometimes offers benefits that other positions do not provide."
on certain occasions or in certain cases but not always
"sometimes she wished she were back in England"
"sometimes her photography is breathtaking"
"sometimes they come for a month; at other times for six months"
On certain occasions, or in certain circumstances, but not always.
"I sometimes forget to water my plants when I'm too busy at work."
In plain English: Sometimes means not always and not never, happening only on certain occasions.
"I sometimes forget to lock the door when I leave for work."
Usage: Use sometimes to indicate that an action occurs on specific occasions rather than every time. It functions as the standard adverbial form of occasionally and does not require a comma when placed at the beginning of a sentence unless it creates ambiguity.
Sometimes comes from Middle English sumtymes, which combined the word for "some" with a suffix meaning "at times." The term entered modern usage to describe actions that occur occasionally or intermittently.