Etymologically, friend derives from the Old English, freond. Enemy, in Old English was a feond. This loss of such a word, takes with it the striking force that one simple letter, changes a friend into an enemy. No doubt the Englishman, before the Invasion understood well how easily a friend could metamorphosis into an enemy, and his language reflected this reality. Sadly, this richness is lost with the corruption of English by Norman-French.