commas with appositives

Restrictive and non-restrictive appositives should be carefully distinguished. Non-restrictive appositives are set off by commas, whereas restrictive appositives are not:

• St. John of the Cross
• Graham St. John, of Hoary Cross
• Her painting Reflections drew a poor response from the public.
• Her first painting, Contrasts, has been little studied.

As in the case of parenthetic expressions, the comma following a non-restrictive appositive cannot be omitted:

• Incorrect: The statement by the Government House Leader, Herb Gray that no changes would be made to salaries paid to Parliamentarians was not unexpected.

In the above example, a comma is required after “Gray”:

• Correct: The statement by the Government House Leader, Herb Gray, that no changes would be made to salaries paid to Parliamentarians was not unexpected.

Non-restrictive appositives in final position are usually preceded by a comma:

• Our supreme governors, the people.

Often, however, the comma is replaced by a colon or dash:

• Tact: a quality that no skilled diplomat can do without.
• Margaret Laurence—perhaps the greatest writer to come out of Manitoba.

If the appositive contains internal commas, it is best introduced by a mark other than the comma.

• Poor: The Pearson government left behind a remarkable legacy, a pension plan, a universal medicare plan and a new flag.

In the above example, a colon would be an improvement over the comma after “legacy”:

• Improved: The Pearson government left behind a remarkable legacy: a pension plan, a universal medicare plan and a new flag.