Hello came into existence in the mid-1800s. It is an alteration of hallo, which was an alteration of holla or hollo. These words were used to attract immediate attention and demand that the listener come to a stop or cease what he or she was doing. Hallo was used to incite hunting dogs.
Hello gained widespread usage though the increased use of the telephone. Alexander Graham Bell had originally suggested the telephone greeting ahoy. But the greeting that stuck was hello, which may have been suggested by Thomas Edison. Hello-girls were the name for the the central telephone exchange operators.
Hullo is the interjection used in Great Britian. However, hello has become just as common.
A more modern use of the word calls into question the common sense or comprehension of the person being addressed. For example, “You’re actually going to eat that rotten peach?! Hello!”
One might assume that hi is an abbreviation of hello. In fact, the first recorded use of hi as a greeting comes from an 1862 speech given by a Kansas Indian. It is also thought that hi is probably a variant of the Middle English hy.
The upbeat greeting howdy was first recorded as a contraction of “how do you do” in 1632. An earlier version comes from “how do ye.”