know
To be aware of through observation, inquiry, or information.
Etymology
From Old English cnāwan, from Proto-Germanic *knēaną, from PIE *ǵneh₃- "to know, to recognise." The initial cluster kn- was once fully pronounced in English. This root is staggeringly productive: "can" (to be able = to know how), "cunning," "keen," "ken," and through Latin and Greek: "cognition," "recognise," "incognito," "noble" (= well-known), "note," "notion," "narrate," "ignore," "diagnosis," and "prognosis."
The Journey: *ǵneh₃- → know
*ǵneh₃-
*knēaną
cnāwan
knowen
know
Cognates Across Languages
These words in other languages descend from the same PIE root *ǵneh₃-. They are not borrowings but independent inheritances from a common ancestor.
| Language | Word |
|---|---|
| Greek | gignṓskō |
| Latin | gnōscere, nōscere |
| Sanskrit | jānā́ti |
| Old Irish | gnáth (known) |
| Lithuanian | žinóti |
| Old Church Slavonic | znati |
Did You Know?
The silent k in "know" was once pronounced. And "can" (I can do it) originally meant "I know how" — from the same PIE root *ǵneh₃-. Even "noble" comes from this root via Latin nōbilis, literally "well-known."
This word descends from the Proto-Indo-European root *ǵneh₃-. See the full root page for descendant trees, sound law references, and scholarly discussion.