[mandibles]

Only a true Texan can tell you the difference between "y'all" and "all y'all".

[__MatrixMan__]

Some sets have a canonical partition. If you're referring to a set of birds or a set of fish, then the correct usage is y'all because those sets canonically partition into themselves.

But if you're referring to a set of birds and fish together, then the usage is "all y'all" because the canonical partition yields more than one subset (one containing birds, and one containing fish). The distinction helps differentiate between whether you mean the superset or one of those subsets.

It works with any other partition which might be obvious (not just birds and fish). If you have two families together, you might avoid "see y'all later" because it could be interpreted that you only expect to see one family later. "see all y'all later", by contrast is unabiguous--you mean both families.

---

Did I get it right? Am I a true Texan?

[4star3star]

Having never given much thought to it, your analysis rings true to my native Texan ears.

There's another usage that comes to mind, though. One might argue that "y'all" borders on a second person plural inclusive of the speaker whereas "all y'all" marks a distinction between the speaker and the others. For instance, a peeved person would be more likely to say, "All y'all can kiss my ass," as opposed to, "Y'all can kiss my ass." "Y'all" by itself is more friendly and self-inclusive than "all y'all", which carries an inherent otherness to it.

[rawgabbit]

It means "everyone with no exceptions".

All y'all need to come to my BBQ tomorrow. I can't eat 50 pounds of brisket by myself.

[stronglikedan]

As a non-Texan, I can usually tell the difference, since "all y'all" is generally followed by "muthafuckers".

[rufus_foreman]

Or preceded by the word "fuck".

[thirdtruck]

Or a Georgian.

[desert_rue]

I believe the Georgian version is different. “Y’all” is singular while “all y’all” is plural.

[Finnucane]

I think that usage is common outside of Texas. A friend from Memphis uses it.

[hotsauceror]

"y'all'd've"

[4star3star]

"y'all'dn't've"

[AdmiralAsshat]

om'n'a go to the store soon!

[PaulDavisThe1st]

<insert scream GIF here>

still, brilliant nonetheless.

[giardini]

"All y'all" is improper Texan primarily used in as a public declaration to convince those present who are NOT Texan, to use the proper expression "y'all" (rather than, say, "all of you", "everyone" or "you" (plural)).

[nosrepa]

Or Dr. Dre.

[o11c]

"all y'all" is an abomination.

[__MatrixMan__]

Using numbers to ab6te words is an abomination. All y'all is fine.