Etymology: Early Middle English aȝȝ , ai , ei : < Old Norse ei , ey , cognate with Old English á ( < *áw ), Middle English o , oo , Old Saxon eo , Old High German eo , io , Middle High German ie , modern German je , Gothic aiw , accusative of aiws ‘age, eternity’ < Germanic *aiwo-z , cognate with Latin aevum . Compare Greek ἀεί , αἰϝεί ‘ever,’ and αἰϝών- ‘age.’ Preceded in English by the native á , ó , which also continued for several centuries as the southern form: the two were combined in the phrase ‘for ay and oo.’ Except in poetry, ay is still northern. The spelling fluctuates between ay and aye : the former is preferable on grounds of etymology, phonology, and analogy. The word rhymes, in the literary speech, and in all the dialects, with the group bay , day , gay , hay , may , way . On the other hand, aye ‘yes’ does not rhyme with these, and should not be written ay . See aye adv. and n.

Etymology: In the later ay me! adopted from, or influenced by, French ahi, aï, Italian ahi; compare Old French aymi!Italian ahime!Spanish ay de mi! The Middle English ey, ei was probably a natural ejaculation; nothing similar is found in Old English: the Middle High German and modern German ey! is probably of independent development; and though there is greater possibility of its being an adoption of Old French aï, this would almost certainly have given ay, ai, which are not found even as variants in Middle English The modern northern dialect ay! eh! or eigh!/eː/ is probably the Middle English ey!, but may be merely the earlier a!, as Old English wá is now wae = /weː/ in the north.