Any
Old English ǣnig (see one, -y1), of Germanic origin; related to Dutch eenig and German einig .
wiktionary
From Middle English any, eny, ony, ani, aniȝ, eniȝ, æniȝ, from Old English ǣniġ(“any”), from Proto-Germanic *ainagaz, from Proto-Germanic *ainaz(“one”), equivalent to one + -y. Cognate to Saterland Frisian eenich(“some”), West Frisian iennich(“only”), Dutch enig(“any, some”), German Low German enig(“some”), German einig(“some”).
etymonline
any (adj., pron.)
"one, a or an, some," Old English ænig (adjective, pronoun) "any, anyone," literally "one-y," from Proto-Germanic *ainagas (source also of Old Saxon enig, Old Norse einigr, Old Frisian enich, Dutch enig, German einig), from PIE root *oi-no- "one, unique." The -y may have diminutive force here.
As a noun, late 12c.; as an adverb, "in any degree," c. 1400. Emphatic form any old______ (British variant: any bloody ______) is recorded from 1896. At any rate is recorded from 1847. Among the large family of compounds beginning with any-, anykyn "any kind" (c. 1300) did not survive, and Anywhen (1831) is rarely used, but OED calls it "common in Southern [English] dialects."
[A]ani refers to single entities, amounts, etc., occurring at random or chosen at random, as being convenient, suitable, to one's liking, etc. It is frequently emphatic and generalizing, having the force of 'any whatever, any at all' and 'any and every'. It is common in questions, conditional clauses, and negative statements, but not in affirmative statements (where som is used instead). [The Middle English Compendium]
