Is the following use of apostrophes correct?  I love to go to Tom's and Nancy's house for dinner.I know this, but I've looked at it so long I just can't remember. Thank you so much.

Expert Answers
linda-allen eNotes educator| Certified Educator

The rule for using an apostrophe to show joint ownership/possession is that the 's follows the second person's name. When you use the construction "Tom's and Nancy's house," you mean Tom's house and Nancy's house separately--two buildings. "Tom and Nancy's house" is the same building.

Here is what wikipedia has to say:

A distinction is made between joint possession (Jason and Sue's emails: the emails of both Jason and Sue), and separate possession (Jason's and Sue's emails: the emails of Jason, and the emails of Sue). Style guides differ only in how much detail they provide concerning these.[3] Their consensus: in joint possession only the last possessor has possessive inflection; in separate possession all the possessors have possessive inflection.

The Chicago Manual of Style online edition says this:

The trick of showing joint possession with a single apostrophe s is possible only with two items that can take an apostrophe s. Hence a car owned by John and Jim can be expressed as “John and Jim’s car.”

A third example comes from the web site apa-format.biz:

• To show joint possession, add an apostrophe and s to only the last word in the
group: e.g.,

Laurel and Hardy's last movie (a movie by the team of Laurel and Hardy.)

• But to show individual possession, add an apostrophe and s to each word in the
group: e.g.,

Fossum's and Day's opinions (the opinions of Fossum, and the opinions of Day)

I'm sure if you check any style manual or do an internet search you'll find even more examples.

The rule of thumb: To show joint possession, use 's only with the second noun.