John, Jack, what's the difference?

[The Big Cheese]

My name is Thomas, but I go by Tom. My brothers is William, he goes by Bill. Why does someone named John often go by Jack?

John Kennedy, but they affectionately called him Jack.

Jack isn't any shorter, both contain 4 characters. I think it's a bit harder to say, John kinda rolls off the tongue. John is easier to type, all with the same hand.

What gives?

[Schnitte]

I'm not an expert in those things, but I guess it's because Jack actually is more comfortable to pronounce (at least it seems so to me, but English is not my native tongue). The o in John is long (you don't say something like "Jn"), whereas the a in Jack is short (it's not really a vowel, the word is rather somthing like "Jk" if pronounced quickly; you don't even need to open your mouth). In everyday usage, I find Jack much more comfortable than John.
The number of characters in the word or the way of typing it will hardly affect the comfort of pronunciation, I would say.

[rowrrbazzle]

"Jack" is just considered friendlier and less formal than "John", like "Tom" and "Thomas".

According to the OED, the origin of "Jack" as a nickname for "John" is disputed. Some think it's derived from the French "Jacques", but it's unknown how it got connected with "John". Another conjectured derivation is along the lines of "Johan" ("John"), "Jan", a "pet" diminutive "Jankin", "Jack".

[mske]

[irrelevant] John seems to almost a taboo name in my family. My grandfather's name was John. He was known as Jack. His son's, my father's, name is John Peter. He uses Peter only. My given names are Michael John. I go by Mike. [/irrelevant]

[Swirdle]

John has a short 'o' in England. Jock is Scottish, as is Ian (or sometimes Iain). Yiannis (pronounced Yaniss) is the Cypriot version of John. Other Jans (pronounced Yan) are from a similar derivation, I believe. So why do the Scots need Jock, Iain, and Ian to add to the John's and Jacks? (Rhetorical)

[kniz]

All my life I thought I had an uncle named Jack (he died many years ago). My father just recently told me that his name was Jack, but he preferred John. My father always hated him and that is why he was Uncle Jack.

[gtzaskar00]

When I was a kid, a friend of my mother's had two sons...

Jack and John... guess she put a lot of thought into that one.

[Spectre of Pithecanthropus]

Some people might prefer to user "Jack" if their last name starts with an "N". To me, "John Nelson" is a little more difficult to enunciate than "Jack Nelson". A similar principle would apply for last names beginning with "M", "ng" (East Asians with Anglo forenames only), and so on. Myself, I always thought John was a great name because the colloquial and formal versions can be exactly the same. As a James, I've always had to contend with using different forms -- James, Jim, or Jimmy -- in different contexts.

[Amp]

I've always wondered how we get Bill out of William. I mean the name is William, not Billiam.

[Ukulele Ike]

Some people might prefer to use "John," if their last name is "Hoff."

The William/Bill thing always threw me, too.

[DrMatrix]

Originally posted by tlmtlm59
Jack isn't any shorter, both contain 4 characters.

Yeah, so? Jack is not an abbreviation for John. It's a nickname. Johnny is a also nickname for John and it's longer.

[cher3]

Just to really confuse things:

I have a father and brother named Jack (not John) and an uncle named Joe (not Joseph.)

[Irishman]

Names are curious, aren't they? Bill for William, Jack for John, Chuck or Chas for Charles, Bob for Robert - some are rather strange.

I know a guy who's given name is Danny, not Daniel or Dan. He frequently runs into people who try to be formal and call him one or the other.

I think you get leading Bs instead of other sounds as a pronouncing simplifier - the B sound is easier to form than the R or the W. Baby-talking toddlers babble and parents applaud them for getting the names right.

But I can't make the connection for Jack and John.

[The Big Cheese]

Originally posted by Amp
I've always wondered how we get Bill out of William. I mean the name is William, not Billiam.

Billiam, I like that.

I just thought there may be a logical answer to it, it seems to be so widespread. Jack and John both seem like common names that are given to people, why call someone by a different first name. WHo knows. We don't call my brother Paul by the name of Peter. We don't call my sister Jane by the name of Jill.

Yes, Johnnie is a nickname for John, ....or would that be Jackie??