Commas with parenthetical expressions and other sentence interrupters

Expressions that are distinctly parenthetical should be set off with commas. Providing supplemental information, they interrupt the flow of a sentence or appear at the end as afterthoughts.

Example sentence with editing. Original sentence: Evolution so far as we know doesn't work this way. Revised sentence: Evolution, so far as we know, doesn't work this way.

Example sentence with editing. Original sentence: Arriving late to an employment interview is quite simply a very bad start. Revised sentence: Arriving late to an employment interview is, quite simply, a very bad start.

Commas should set off nouns of direct address, the words yes and no, interrogative tags, and mild interjections.

Example sentence with editing. Original sentence: Forgive us Dr. Atkins for having rolls with dinner. Revised sentence: Forgive us, Dr. Atkins, for having rolls with dinner.

Note that these examples are more characteristic of speaking than writing.

Exercise: Major uses of the comma 1

Exercise: Major uses of the comma 2

Exercise: All uses of the comma