Dear John

I have been trying to figure out the derivation and meaning of the name English names John, Jonas, and Jonah. I've seen conflicting information concerning this. For example,

• Does John mean "God is gracious" or "He (God) accomplishes"?
• It's pretty clear that Jonah is from the Hebrew word for "dove", but is Jonas a variation of John or Jonah? Also, is Jonas Lithuanian or Greek?
  

I found what looks like reliable information at BehindTheName.com. That site has the following in its entry for John:

English form of Johannes, which was the Latin form of the Greek name Ioannes, itself derived from the Hebrew name Yochanan meaning "YAHWEH is gracious".

And the following information appears for Jonas:

JÓNAS m
Usage: Icelandic
Icelandic form of JONAH

JONAS (1) m
Usage: Lithuanian
Lithuanian form of JOHN

JONAS (2) m
Usage: Biblical (Variant)
Greek form of JONAH

(Just another example of the kind of stuff you probably won't learn anyplace else...)