Business Writing Essentials
When a noun owns something, we use 's to show that ownership:
We needed Amy's boss's signature on Bob's and Ben's individual reports, but instead got it on Amy and Ann's combined report.
When a plural noun that ends in s owns something, we just use the apostrophe by itself:
The supervisors' decisions are in the employees' best interests.
When a pronoun owns something, however, it can get complicated. For example, singular personal pronouns have their ownership built into the words themselves:
His report was combined with hers. That report is neither yours nor ours nor theirs. Its author is unknown.
That last little sentence is the screaming elephant in the room. Do not take the easy way out and always type it's hoping to get it right about half the time. Instead, learn the correct way to do it. Your coworkers will think you're an outstanding professional and a brilliant scholar. And that tends to count for something.
There is an easy way to always get it right. Memorize the following phrase:
His, hers, its, no apostrophe fits.
There are absolutely no exceptions to this rule about punctuating its and it's. Nada. Zip.
But, just to keep things interesting, there are impersonal pronouns that do not have ownership built into them and therefore require the addition of 's to show ownership:
If it is one's opinion that nobody's report was any better than anybody else's, then we might as well all go home and phone it in.
Note: Rebuttals and Rebukes
Careless New Hire: "What's the big deal, anyway? Who cares whether I use its or it's?"
Judgmental Boss, thinking: "What kind of lazy fool did we hire?"
Analytical New Hire: "Emailing and messaging have created an abbreviated approach to writing and punctuation. But that's okay, because we should write the way we speak. At work we work fast and we speak fast, so accuracy in mechanics should be sacrificed so we can communicate as quickly as possible."
Responsive Boss: "Messaging, sure, it might make sense. But email? No way. Every one of your important emails should be as correct and clear as if you had typed and mailed an old-fashioned letter. Take the time to be professional: raises and promotions will follow."
If you find yourself thinking hard to justify a habit, ask yourself if you are doing it because you simply don't want to change, or because you truly believe your way of doing things would be highly beneficial to your employer.
Course: Business Writing Essentials