Perhaps Joe Biden should lay off the memos for a while. His last one didn’t go so well.

Today’s memo begins with a cheap shot at brownie points: praise for his wife. “My wife Jill is an extraordinary woman.”

Nonessential elements can be removed from a sentence without changing the meaning; they are set off with commas. Here’s an example: Joe’s only sister, Valerie, attended the rally. Since Joe has only one sister, her name is not essential to understanding the sentence.

If he had multiple sisters, it would be necessary to specify which one attended the rally, and hence, no comma would be needed. The sister’s name would become an essential element, which is not set off with commas.

Joe’s punctuation implies he is polygamous. Probably not an idea he’d like to convey right now.

See how high the grammatical stakes are?