Yes. Jack is a standard nickname for John. (Compare Dick and Richard or Jim and James )
Yes, Jack can be a common nickname for Jonathan.
No, it was John. Jack is a somewhat common nickname for John.
His name was Jack Rackham. His nickname was Calico Jack
yes Jack was John's nickname
His nickname is Black Jack
"Black Jack" or "N*gger Jack".
'Jack' is a common nickname for someone whose name is 'John.'
"Black Jack" or "N*gger Jack".
John F. Kennedy was often called "Jack"/
JACK
his middle initial is Fitzgerald His nickname was Jack.
John Fitzgerald Kennedy (official name) was called Jack Kennedy (nickname) by his family and friends. Jack is a common nickname for John.