Between is the word for the space, the time or the gap that separates two things. The gap between two parked cars, the seat between your mum and your sister, the years between school and your first job.
It stretches from place to time to relationship: between Tuesday and Friday, a match between two teams, the difference between the copies, an argument between neighbours. Between and among are not the same — between takes two, or several things you are naming one by one; among puts you inside a crowd nobody is counting (lost among the trees). It hides inside fixed phrases: in between, few and far between, between you and me. And the pronoun after it stays in the object form, so it is between you and me, never between you and I.
1prepositionbetweenIn or through the space that separates two people, places or things.~10%
“The cat squeezed between the fence and the wall.”
2prepositionperiodIn the period that separates two times or events.~2%
“The shop is closed between one and two.”
3prepositionconnectingConnecting, comparing or dividing two or more people or things.~67%
“The treaty between the two countries lasted forty years.”
5adverbseparatingIn the space or time separating two things, with no noun following.~2%
“Two tall houses with a narrow alley between.”
Shares are an estimate: a language model read 20 sentences found in the wild and placed 20 of them on a sense — a count of our sample, not a measurement of English.
Old English said betwēonum, which unpacks as 'by the two, near both' — be plus a Proto-Germanic word *twīhnaz, 'two each'. That second half is the same two you can still see in twin and in the old word twain, and the line runs back to the Proto-Indo-European word for two, *dwóh₁. Between has been counting since before English was written down.
Proto-Indo-European
*dwóh₁
Proto-Germanic
*bi- — be-
Old English
betwēonum — between, among
Middle English
betwene
English, today
between
Built from
From Middle English betwene, from Old English betwēonum (“between, among”) literally “by the two, near both”, from Proto-Germanic bi- (“be-”) + twīhnaz (“two each”), corresponding to be + twain. Cognate with Scots between (“between”), Scots atween (“between”), Gothic 𐍄𐍅𐌴𐌹𐌷𐌽𐌰𐌹 (“two each”), Old English betweoh (“between”), Old English twinn (“double, twofold”). More at betwixt, twin. More distantly related to Ancient Greek διά (“through, across, by, over”) whence English dia- (“through, across, between”). For the meaning development also compare with хооронд (“between”), connected with хоёр (“two”).
Etymology from Wiktionary, CC BY-SA