Day 3: Elements of Style

"Enclose parenthetical expressions between commas."

As in: "The best way to see a country, unless you are pressed for time, is to travel on foot."

After starting with possessive forms and serial punctuation, two sections well within common knowledge, this section presents the subtlety and detail I expect when I hear the name "The Elements of Style." The case of parenthetical expressions creates difficulty due to the rules of application. Two similar sounding phrases might have opposite punctuation. For example:

My eldest cousin, Matthew, works for PircewaterhouseCoopers.

My aunt Kat has a beautiful daughter.

Although the two sentences sound similar, the name Matthew gets set apart because it adds no new information. I have only one eldest cousin. In the second case Kat is not separated since it is necessary to specify which of my aunts I mean. In general a nonrestrictive clause like Matthew should be set apart, and a restrictive clause like Kat should not. A good rule of thumb to determine if a phrase should be set apart is to try to form two sentences from the sentence in question. The first splits nicely, and the second does not.

My eldest cousin is named Matthew. He works for PircewaterhouseCoopers.

My aunt is named Kat. She has a beautiful daughter.

In no cases, however, should one comma be applied without the other. In addition parenthetical expressions should be used with dates and titles, and when one uses a name or title as a direct address.