From Rick:

Sometimes pronouns, especially the possessive ones, give us trouble, particularly when we’re dealing with a compound ones. I recently came across two issues in a manuscript I was editing. The first one represents simple pronouns confusion:

(1) Children tugged at their parents, desperate to hasten their slow strides with their own enthusiasm for the festivities.

The problem is that “their” refers to two different groups. The first and third refer to the children, but the second one refers to the parents. In this case, it’s probably not a showstopper for a reader, but you don’t want to risk this type of confusion. Anything that causes a reader to stop and backtrack is a potential put-off. And if it happens often, you may lose your reader and possibly ending up with a bad review.

Okay, that one wasn’t too bad, but here’s another that is certain to cause some readers to tweak:

(2) The princess turned to Jason. “Your brothers will be the prince and I’s honored guests at the festival.”

Yes, I know it’s in dialogue and even though it’s poor grammar to say “I’s” (you do know it’s bad grammar, right?). Granted we may well hear this said in our daily lives (just as we hear people say “I should have went”), but unless you have establish that your character’s speech and grammar are bad by intent, then you shouldn’t have him say this. In this case, it’s a prince saying it (in a fantasy novel), so a reader isn’t likely to believe a prince would use such incredibly poor grammar.

So how should that sentence be written? First, let’s pull the two possessives apart and look at each element of the possessive separately to help you understand the problem.

“Your brothers will be the prince honored guests at the festival.”

“Your brothers will be I’s honored guests at the festival.”

Clearly we would say neither of these (and I purpose left it as “prince” not “prince’s”. The two sentences would be properly written this way:

“Your brothers will be the prince’s honored guests at the festival.”

“Your brothers will be my honored guests at the festival.”

Therefore, the combination should be “Your brothers will be the prince’s and my honored guests at the festival.”

Remember this: NO possessive pronoun ever take an apostrophe! (no I’s, my’s allowed). And let’s not forget that “it’s” represents “it is” and that the possessive form “its” (The dog buried its bone in the garden) doesn’t have an apostrophe.

But example (2) represents another grammatical problem when dealing with compound possessives (two or more people referred to as the possessives). The rule is that when something belongs to both or all of the people mentioned, only the LAST one is written as a possessive.

John and Mary’s car is parked on the street. (John and Mary own the car jointly.)

Tyler, Jeff, and Sam’s toys are scattered all over the house. (The three boys all own the toys.)

John’s and Mary’s cars are parked on the street. (John and Mary have separate cars.)

Alan’s and Carol’s clothes are packed for their trip. (Alan and Carol have separate clothes. If we said “Alan and Carol’s clothes are packed” then we might wonder if they’re cross-dressers.)

Steve’s and Wendy’s vacations are booked in June. (separate vacations)

Going back to the example with the prince, a better way to write that sentence would be to avoid the potentially awkward possessive in the first place. It’s a joint invitation, so saying “the prince’s and my…” still isn’t perfectly correct. Here are some better ways to word it:

“Your brothers will be the honored guests of the prince and me at the festival.” (not “I”)

“Your brother will be our honored guests at the festival.”

“The prince and I want you to be our honored guests at the festival.”

This is a case where rewording might be a better option than simply attempting to fix the grammar flaw.

Scott and I handle these and other possessive forms and plurals rather extensively in the chapter on apostrophes in “Punctuation For Fiction Writers.”

Be careful in your writing to watch for these easy-to-miss grammar errors and watch out for using the correct pronouns after prepositions:

Use “between you and me” not “between you and I.”

–Rick