What is the plural form of the word Harry?
The plural form is Harrys:
There are two Harrys in my class, Harry Green and Harry Brown.
Names ending in 'y' are made plural by simply adding an 's' instead of changing the 'y' to 'ies'. Marys and Sallys, Billys and Bobbys don't' care to be Maries and Sallies, or Billies and Bobbies. The Kennedys are not Kennedies, and the Harrys are not Harries.