since
conj.conj. used to give a reason for something. You use it when the person you are talking to already knows the facts you are mentioning.
conj. used to introduce a subordinate clause that provides a reason or explanation for the main clause. Often implies that the reason is already known to the listener or is a logical consequence of the situation.
Since it is raining, we should stay inside.
Since the office is closed for the holiday, all staff members are working from home today.
Since the initial data proved inconclusive, the research team decided to extend the study for another six months to ensure the results were statistically significant.
From Middle English syns, synnes, contraction of earlier sithens, sithence, from sithen (“after, since”) ( + -s, adverbial genitive suffix), from Old English sīþþan, from the phrase sīþ þǣm (“after/since that (time)”), from sīþ (“since, after”) + þǣm dative singular of þæt. Cognate with Dutch sinds (“since”), German seit (“since”), Danish siden (“since”), Icelandic síðan (“since”) Scots syne (“since”).
When used as a conjunction of reason, it typically appears at the beginning of a sentence or after a comma.
Since three years I live here.I have lived here for three years.Learners often use 'since' to describe a duration of time; 'since' must refer to a specific starting point, while 'for' describes the length of time.