Commas, Colons, Semicolons

1. Don't use a comma to join two independent clauses. The result is a comma splice.

Don't write: We tried to splice the film with cellophane tape, the film broke again when we ran the projector.

Like the tape on the broken film, a comma is not strong enough to hold these two clauses together.

 Solutions Substitute a semi-colon for the comma. We tried to splice the film with cellophane tape; the film broke again when we ran the projector. Use a coordinating conjunction (and, but, or, for, nor, yet). We tried to splice the film with cellophane tape, but the film broke again when we ran the projector. (Note that the writer maintains the comma before but when but introduces an independent clause.) Use a subordinating conjunction. Although we tried to splice the film with cellophane tape, the film broke again when we ran the projector. Break the sentence into two sentences. We tried to splice the film with cellophane tape. The film broke again when we ran the projector.

2. Don't use a semicolon to join an independent clause to a subordinate clause or a phrase.

Don't write: The novelist Frances Burney achieved success at a young age; a rare feat for an author.

 Solutions Use a comma to join a noun phrase to an independent clause. The novelist Frances Burney achieved success at a young age, a rare feat for an author. Use a colon if the noun phrase repeats the meaning of a phrase in the independent clause. The novelist Frances Burney achieved a rare feat for an author: success at a young age.

3. Combine a semi-colon with a comma when using however or another conjunctive adverb to join two independent clauses.

Write: Online registration has made it easier to schedule courses; however, I don't have access to a computer.

If the adverb does not come between two independent clauses, set it off with two commas.

Write: In the beginning, however, I was nervous about talking on the phone with strangers.

4. Use colons to introduce a list or an example (the colon takes the place of the phrase such as):

Write: The titles of Octavia Butler's novels suggest her interests in Psychology and Sociology: Adulthood Rites, Kindred, Mind of My Mind, and Survivor.

Hyphens and Dashes

1. Use hyphens to connect compound words and numbers, especially when they serve as adjectives.

Compare the following:

Francis Bacon articulated the criteria of the New Science at the beginning of the seventeenth century.

Francis Bacon was a seventeenth-century author.

2. Use dashes (sparingly) to set off comments inserted in a sentence or to indicate emphasis or change of thought. Type dashes as a long line, two hyphens, or a hypen surrounded by spaces.

The total eclipse of the sun - the last in this century - can be viewed in southern England as well as Asia.

The concert will go on as planned - unless the band's bus breaks down again.

Quotation Marks

1. In American usage, place commas and periods inside quotation marks unless they precede parentheses:

Write: Audre Lorde chills her audience by fusing images of beauty with shouts of racism in "Every Traveler has One Vermont Poem."

Write: New York City itself, not Ringling Brothers, is the subject of "Big Apple Circus" (Lorde 45).

2. Put semi-colons and colons outside quotation marks:

Write: We began the class by discussing Cicero's essay, "On Friendship"; Shakespeare obviously had this essay in mind when he wrote The Winter's Tale.

3. In American usage, indicate quotations-within-quotations by using single quotation marks:

Write: Sherry Turkle notes, "We remember that Lacan stresses that the ego is formed by a composite of false and distorted introjections so that 'I' and 'Other' are inextricably confused in the unconscious language of the self" (Psychoanalytic Politics 103).