Imagine that I want to write a sentence indicating that a secret lair belonging to my co-conspirator Nemo and myself has been discovered. How would I indicate joint possession of the lair? Mine and Nemo’s secret lair? I and Nemo’s secret lair? Nemo’s and I secret lair? Nemo’s and my secret lair?
Correctly, I should write Nemo’s and my secret lair.
Joint possession is a construction that a lot of writers struggle with, however. But unlike the combination key on the secret lair, the construction isn’t difficult to decode.
To indicate joint possession of an object or place, first, determine who the subjects are by breaking them apart. The first subject is Nemo – that’s easy enough. The second subject is I.
This is where it gets tricky. You then replace each subject – Nemo and I — with the possessive form of each: Nemo’s and my.
The first subject, Nemo, shouldn’t be too hard to make possessive – an “s” is all that is needed. (Please don’t forget the apostrophe!) The second subject is I. You might think, then, that the possessive pronoun would then just be I, but because I am speaking of something (the secret lair) that I possess, I’ll want to make this pronoun a possessive pronoun: my.
It’s easy enough to figure out if you break up the subject as I did a few moments ago. You would never say, “I secret lair” in order to indicate that the lair is yours. Neither would you say, “Mine secret lair.” No, you would say “my secret lair.”
Thus, once I’ve broken apart the subject, I can join the two possessive forms: Nemo’s and my secret lair.
And now, I had better get cracking on moving the lair before the good guys show up.