Kim’s question: “In both writing and speaking, how do I refer to something that belongs to more than one person? For example, a report that Bill and I worked on – ‘the report is Bill’s and mine’ or ‘the report is my and Bill’s.’ What is the correct way to state this?”
BizWritingTip response: This is a great question. It involves a standard rule and then the exception.
First, when you have two nouns, it is considered a compound noun. If you need to show possession with a compound noun, use an apostrophe. But where does the apostrophe get placed?
If both nouns own the same thing, the apostrophe is placed after the last noun. If both nouns possess different things, then an apostrophe must be added to each.
Bill and Susan’s report will be ready for printing tomorrow. (One report)
Bill’s and Susan’s reports will be ready for printing tomorrow. (Two reports)
The report was Bill and Susan’s. (One report)
The reports were Bill’s and Susan’s. (Two reports)
However, when a personal pronoun (I, you, he, she, we or they ) is involved, there is a slight difference. You place the apostrophe on the noun only. Personal possessive pronouns never have an apostrophe as they are already possessive (my, mine, his, hers, ours, yours). Note: The noun comes first.
Bill’s and my report will be ready for printing tomorrow.
The report is his and mine. (Never use an apostrophe with a possessive personal pronoun.)
The report is Bill’s and hers.
The report is Bill’s and mine. (The noun is always placed first.)