A joining of equals: a look at coordinating conjunctions

The coordinating conjunctions—and, but, for, nor, or—are, when I am wearing my copyeditor's hat, my favorite parts of speech, for writers make few mistakes when using them.

cats and cushion covers (A comma after "cats" would be wrong.)

Coordinating conjunctions are conjunctions that join sentence elements of the same type (noun, predicate, clause, and so on) and weight (they do not join independent and dependent clauses).

I won't spell out the rules for using coordinating conjunctions. (If you have a question, feel free to ask in the comments.) Instead, I'll focus on the problems I most often see.

Tricky point 1: "including"

A list following the word "including" should contain "and," not "or":

• I bought groceries yesterday, including eggs, milk, and bread.

"Including" means that all of the items that follow are part of the whole. So "and" is the proper conjunction.

If you give a complete list of items, then do not use "including."

Tricky point 2: lists of options

The word "and/or" is not an error, but it makes your sentence clunk. Use "or" when you have a list of choices:

• Please bring ouzo, grapes, or cheese to the party.

The hostess does not forbid you to bring grapes if you bring cheese; she merely offers options. As in many sentences with "or," the idea is not to limit the choices to one item but to say that at least one item is needed. Save "and/or" for legal writing or other occasions in which you need a belt-and-suspenders approach.

When you need "or" to limit the options to one, try a construction such as this:

• You may have either plum sorbet or chocolate-covered ants for dessert.

Tricky point 3: punctuation of two elements

When two complete sentences are joined by a coordinating conjunction, always put a comma before the "and" unless the sentences are very short.

• Mary pieces her quilts by hand, but I prefer to use a sewing machine.

When you have two predicates (or two adjectives or prepositional phrases), treat them as items in a series. Two items in a series are never separated by a comma unless a misunderstand could result.

• "You were my last hope," the dragon said and blew his nose. (no chance of confusion)
• "You were my last hope," the dragon said, and cried. (Without the comma, the reader may think he said it and then cried it out.)

If you want or need to create a space between two predicates, rewriting the sentence is preferable to using a comma:

• "You were my last hope," the dragon said and then loudly blew his nose. 

• "You were my last hope," the dragon said. He pulled out a lacy handkerchief and blew his nose.

• "You were my last hope," the dragon said. He blew his nose.

• "You were my last hope." The dragon blew his nose.

Tricky point 4: nonparallel elements

When elements in a row are not parallel, do not treat them as a series. An example of this mistake would be, "The tomcat is long, white, and wears a pink rhinestone collar." This sentence is wrong because there are two levels of parallel constructions here: "long" and "white" are parallel adjectives, and "is long [and] white" and "wears a ... collar" are parallel predicates. (Also, tomcats should not wear pink rhinestone collars.) The punctuation should reflect these two levels:

• The tomcat is long and white and wears a pink rhinestone collar.

• The tomcat is long and white, and he wears a pink rhinestone collar.

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Coming soon

• correlative conjunctions (both . . . and, neither . . . nor, not . . . but, not only . . . but also, whether . . . or)

• interview with author Steve Malley