what are the origins of hi, hey, hello?

What are the origins of hi, hey and hello? Are they related?

'Hey' ( perhaps originally a natural expression) appears to be at the origin of 'hi', while 'hello' seems to have no connection with the previous two terms and a different origin (mainly as a telephone greeting).

Hi:

• greeting, 1862, American English (first recorded reference is to speech of a Kansas Indian), originally to attract attention (15c.), probably a variant of Middle English hy, hey (late 15c.) also an exclamation to call attention. Extended form hiya attested from 1940.

Hey:

• c.1200, variously, in Middle English, hei, hai, ai, he, heh, expressing challenge, rebuttal, anger, derision, sorrow, or concern; also a shout of encouragement to hunting dogs. Possibly a natural expression (compare Roman eho, Greek eia, German hei). Þa onswerede þe an swiðe prudeliche, `Hei! hwuch wis read of se icudd keiser!' ["St. Katherine of Alexandria," c.1200] In Latin, hei was a cry of grief or fear; but heia, eia was an interjection denoting joy.

Hello :

• 1883, alteration of hallo, itself an alteration of holla, hollo, a shout to attract attention, which seems to go back to at least c.1400. Perhaps from holla! "stop, cease." OED cites Old High German hala, hola, emphatic imperative of halon, holon "to fetch," "used especially in hailing a ferryman." Fowler lists halloo, hallo, halloa, halloo, hello, hillo, hilloa, holla, holler, hollo, halloa, hollow, hullo, and writes, "The multiplicity of forms is bewildering ...."Popularity as a greeting coincides with use of the telephone, where it won out over Alexander Graham Bell's suggestion, ahoy. Central telephone exchange operators were known as hello-girls (1889).
  • Hello, formerly an Americanism, is now nearly as common as hullo in Britain (Say who you are; do not just say 'hello' is the warning given in our telephone directories) and the Englishman cannot be expected to give up the right to say hello if he likes it better than his native hullo. [H.W. Fowler, "A Dictionary of Modern English Usage," 1926]

source: Etymonline.com

The question of the etymology of hello is a fascinating puzzle.

According to the the OED it was originally an Americanism derived from the British hallo which has its origins in the Old German "halâ, holâ, emphatic imperative of halôn, holôn to fetch, used especially in hailing a ferryman."

However other dictionaries (such as Dictionary.com) cite an origin in the Romance word "hola", an interjection meaning Stop!, literally O la! (Woh there!) ref: Le Tresor de la langue Francaise.

To muddy the waters, other etymologies for hola exist. etimologias.dechile.net cites the Spanish word "Hola" as having a Classical Greek origin in ούλε (Good health, used by Homer : Odyssey Chapter 24 verse 402). This Greek word appears to share PE roots with German heil which is also a greeting meaning health (cognate with English hale).

Hi and hey (according to all sources) have their origins in the Germanic languages where many modern cognates exist, usually as hei or hej. The ubiquity of "Hey" soundalikes in completely unrelated languages ("Burmese ဟေး (he:), Finnish hei, Unami hè, and Mandarin Chinese 哎 (āi), and various sound-alikes as Roman eho, Greek εἴα (eía), Latin eia, Sanskrit हे (he)" : Wiktionary.org) suggests "Hey" is simply a natural human expression (OED).

Which, to come full circle, may explain the success of similar-sounding interjections such as "hello".

There may be even parallels in Semitic languages. If I remember right, addressing a person (vocative case) is done in Tunesian with the particle /yæ/, very similar to he.

Latin had a special vocative ending for names of the first declension. So Marcus got the vocative form Marce /'marke/. One might assume that it has its origin in Markus/Marco+he/e.