Why “know” is a great word
To possess a certainty about something as a fact or truth, or to be familiar with through experience or learning. From Middle English knowen, from Old English cnāwan ("to know, perceive, recognise"), from Proto-West Germanic *knāan, from Proto-Germanic *knēaną ("to know"), from Proto-Indo-European *ǵneh₃- ("to know"). Unlike "recognize," which is the flash of identification in a crowd, or "understand," which implies the work of fitting a fact into a framework, to know is a foundational state of awareness. It is the cold granite of a mathematical proof; the intimate, wordless texture of a lover’s hand; the devastating clarity of a diagnosis—the private territories of the mind where doubt has been exiled. It is a condition so basic to consciousness that its absence would unmoor the world entirely.
Etymology
From Middle English knowen, from Old English cnāwan (“to know, perceive, recognise”), from Proto-West Germanic *knāan, from Proto-Germanic *knēaną (“to know”), from Proto-Indo-European *ǵneh₃- (“to know”).
Cognates
from Indo-European: Latin gnoscō, Latin cognoscō (Spanish conocer, French connaître, Romanian cunoaște, Italian conoscere, Portuguese conhecer), Ancient Greek γνωρίζω (gnōrízō, “to know”) and γνῶσις (gnôsis, “knowledge”), Albanian njoh (“to know, recognise”), Russian знать (znatʹ, “to know”), Lithuanian žinoti (“to know”), and Persian شناختن (šenâxtan, “to know”).
from Proto-Germanic: Scots knaw (“to know, recognise”), Icelandic knega (“to know, know how to, be able”), Old High German knājan (“to know, recognise”), Old Norse kná (“to know how”). Remotely related also Dutch and G