\"I's\" Is Technically Wrong. It's Also Everywhere.
You've said it. Or you've heard it. "Have you seen Margaret and I's cat?" It hits a little funny. It sounds like a mistake. And yet it communicates exactly what you meant, instantly, and nothing else does quite as cleanly.
Welcome to one of English's messiest grammar corners.
The Problem Nobody Solved
English has a gap. When you want to show joint possession and you're one of the owners, the options get awkward fast. "Your mother and my car" works but lands strangely in certain contexts. "Your mother's and my car" is technically correct and sounds like you're reading from a style guide at gunpoint. So speakers, being practical creatures, invented a workaround: stick an s on "I" and call it done. "Your mother and I's car."
Prescriptivists hate this. Actual humans keep using it anyway.
Married with Children, Grammar Pioneer
Mark Liberman went looking for the earliest documented example of this construction using the COCA corpus, a massive database of real American English usage. What he found: a subtitle from a 1992 episode of Married with Children.
The line: "It's your mother and I's quality time."
The Bundy household. Ground zero for possessive "I's" in the written record.
This is either deeply funny or weirdly fitting, depending on your relationship with 90s sitcoms. Subtitle writers, working fast, capturing dialogue as it actually happens, wrote down what people actually say. And what people actually say includes "I's."
67 Times and Counting
The COCA corpus doesn't just have that one Married with Children subtitle. It has 67 other examples of this usage. Sixty-seven. That's not a fluke. That's a pattern. That's language doing what language does: finding solutions to gaps, even when the solution makes editors wince.
One possibility is that "I's" as a possessive has been spreading quietly in speech for decades, only showing up in written corpora when someone transcribed dialogue or wrote down a real conversation. The 1992 example might be the earliest documented, not the earliest used.
A Completely Different "I's"
There's an older appearance of "I's" worth knowing about. The 1921 play Granny Boling includes the line: "I's lived a long time, boy, and I's seed a heap of trouble." This is a different creature entirely. Here "I's" is a dialectal form, not a possessive. Same spelling, completely different job.
Language is full of these near-collisions. Two separate problems, two separate solutions, both landing on the same three letters.
What Word People Should Take From This
If you've ever been mid-Wordle-argument about whether something "counts," you already understand that actual usage and official rules are different things. "I's" as a possessive doesn't appear in any style guide. It appears in 67 corpus examples and a Married with Children subtitle, and it solves a real problem that the official options solve badly.
Language is messy and alive. The subtitlers wrote down what they heard. The corpus captured what people said. And somewhere out there, someone is saying "Margaret and I's cat" right now, and everyone in the room understands them perfectly.
That's not wrong. That's how this whole thing works.
Source: Languagelog