myEtymology.com: English etymology of certainly

Etymology of the English word certainly

the English word certainly

derived from the English word certain

derived from the Old French word certain

derived from the Vulgar Latin root *certanus

derived from the Latin word certus (fixed, settled, firm)

derived from the Medieval Latin word cernere (sift, separate, distinguish)

derived from the Proto-Indo-European root *krei-

using the English suffix -ly