Q. I can’t wrap my brain around this question re appositives. In the following sentence, is the man’s name restrictive or nonrestrictive? Ask Ruth’s childhood friend Tom Jones to help.

A. Unfortunately, it’s ambiguous. It used to be that a lack of commas signaled restriction: that is, the meaning of “friend” in your sentence would be restricted to Tom Jones, implying that Ruth had other friends as well. Commas (Ask Ruth’s childhood friend, Tom Jones, to help) signaled nonrestriction: that Tom Jones was Ruth’s only childhood friend, so his actual name is ancillary, disposable information. It was a pretty good system. Nowadays, however, commas in nonrestrictive constructions have become optional, which is fine when the most likely meaning is obvious (as in “my wife Georgia”) but unhelpful in a sentence like yours. And writers everywhere add commas where they aren’t needed (Astronaut, Neil Armstrong, waved to the crowd), which adds to the confusion.