since

自…以來、從…開始

She has lived in this city since 2015.

她從二○一五年起就住在這座城市。

自從、自…以來

I haven't seen him since we graduated from college.

自從我們大學畢業後，我就沒再見過他。

既然、因為、由於

Since you're already here, you might as well help.

既然你都來了，不如就幫個忙。

從那時以來、之後

He left home at eighteen and has not returned since.

他十八歲離家，之後就沒再回來過。

早已、久已多與 long 連用

The old bookstore has long since closed down.

那家老書店早就已經關門了。