Definition
From a specific time in the past until now; used to indicate that something has happened after a certain point in time.
Example
I have lived here since 2010.
Conversation

Have you talked to Sarah since she moved away?

Not really, I lost touch after she left.

That's too bad! I thought you were close friends since high school.

Yeah, we were, but life just got busy, I guess.
Synonyms & Antonyms
Definition
From a specific time in the past until now, or because of something.
Example
I have lived here since 2010.
Conversation

Have you been to that new cafe downtown?

Not yet! I've heard great things about it, though.

You should go, especially since they have amazing pastries.
Definition
From a particular time in the past until now or until another time.
Example
They have been friends since childhood.
Conversation

Hey, have you seen Sarah lately?

Not really, I haven't talked to her since last month.

I wonder what she's been up to since then.
Root Explanation
Since originates from Old English 'sincan', meaning to sink or to fall. It refers to a point in time from which something has occurred or continued.
Memory Tip
Think of 'since' as marking the point in time from which something has 'fallen' or started.
Visually Confused Words
sine
sice
silence
science
yince
wince
vince
tsine