A reader writes:
I often hear people say sentences like, “His and I’s property.” “Jimmy and I’s vacation.” I have tried to explain that I’s is not an acceptable genitive pronoun, but I have heard it from many different sources here in Utah. Could you write something about this in your posts?
Because the first person pronoun I has the possessive form my, the construction “Jimmy and I’s vacation” screams “nonstandard English.”
I’ve seen the construction defended as a “phrasal possessive.” The idea is that the apostrophe s is not being added to the subject pronoun I, but to the phrase, “Jimmy and I.”
This argument may satisfy students of linguistics, but it does not satisfy speakers of standard English.
Changing “Jimmy and I’s vacation” to “Jimmy’s and my vacation” may look better, but it does not address the problem. The vacation belongs to two people and my denotes singular possession. The vacation is still jointly owned. According to the standard rule,
if two people possess something jointly, only one apostrophe is needed:
“Alice and Mary’s stove” One stove. The stove is owned by Alice and Mary.
“Alice and Mary’s cats” More than one cat, but all cats belong to Alice and Mary jointly.
If two people own separate things, an apostrophe is added to each name:
“Alice’s and Mary’s cats.” More than one cat. Each woman owns one or more cats.
The problem arises when the speaker wants to link third person with first person, as in “Jimmy and I’s vacation” or “His and I’s property.”
Standard English requires a different construction. One possibility:
Our vacation, Jimmy’s and mine.
Our property, his and mine.
Avoid Awkward Joint Possessives