Commas with Expressions

Use commas to enclose interruption words, phrases, or clauses, as in the following examples:

The student senate, predictably, opposes the increase in tuition for next semester.
The senators, it seems, are seeking an injunction in district court to stop the administrator’s plans.

Also use commas to set off conversational expressions, as in the following examples:

“Well, I’m not sure,” said the former president.
No, you may not leave until your homework is done.

Use commas to mark a contrast. Consider these examples:

Owning a car is a nuisance, not a necessity.
Marilyn had seen a lunar eclipse, but never a solar one.

Finally, use commas to keep ideas clear and distinct inside expressions:

Some critics believe that whatever is, is wrong.
Those who can, do; those who can’t, complain.

Which sentence is correct? Eric has toured Europe and the Far East but not South America. They checked with the State Department, in fact, before they made their final travel plans.