The word HELLO was came in so frantic after the invention of telephone, but hello was first written with this spelling in 1833 col.David's book called sketch and eccentricity.so coming to the points of argument Where most would say Graham bell is the one who came up with this word but Thomas Alva Edison is the one coined the paunchy greeting to start the convestion in telephone with hello, where bell came up with a word AHOY.
Where as goodbye is the contraction of god be with ye(you). But this word has no defiant point of origin but the first document of use was in 16th century of a scholar Gabriel Harvey.
