> Greek, meanwhile, uses "Γειά σου" (pronounced "yah-soo") as a typical informal greeting, offering a wish for health rather than a simple salutation.

Ironically, the root of "salutation" in latin is "salutare," to wish good health.

> According to linguists, elongated variations such as "heyyy" could be construed as flirtatious, "hellaw" might suggest you're from the southern US, "howdy" from western US, and the clipped "hi" may indicate a curt disposition.

Surely "howdy" derives from "how do you do?" and not "hello."