COLONS

Use a colon only after an independent clause (a complete sentence) to introduce a concluding explanation, a list, an appositive, or a quotation. The element it introduces may or may not be an independent clause.

1.        Explanation
                    The business school caters to working students: it offers special evening
                                courses in finance and management.

2.        List
                    If you really want to lose weight, you need give up only three things: breakfast,
                                lunch, and dinner.

                    The students' demands included the following: an expanded menu in the cafeteria,
                                 improved janitorial services, and more up-to-date textbooks.

3.        Appositive
                    The Metropolitan Museum in New York City now owns the best-known works of
                                Louis Tiffany's studio: those wonderful stained-glass windows.

4.       Quotation
                    The little boy in E.T. did say something neat: "How do you explain school to a
                                higher intelligence?" - George F. Will

                NOT        The three meals are: breakfast, lunch, and dinner.
                                People misuse punctuation marks such as: colons, semicolons, and dashes.
                                Handbooks provide valuable information about grammatical conventions
                                             including: subject-verb agreement, pronoun-antecedent agreement,
                                             and parallelism.

SEMICOLONS

1.        Use a semicolon instead of a period between independent clauses that are closely related
                    in meaning.

                    This is my husband's second marriage; it's the first for me.

2.        Use a semicolon when conjunctive adverbs (therefore, however, etc.) or other
                    transitional expressions (in fact, as a result, etc.) connect two independent
                    clauses.

                    The average annual rainfall in Death Valley is about two inches; nevertheless,
                                hundreds of plant and animal species survive and even thrive there.

3.        Use a semicolon between long or comma-containing items in a series.

                    Functioning as assistant chefs, the students chopped onions, green peppers, and
                                parsley; sliced chicken and duck meat into strips; started a broth
                                simmering; and filled a large, low, copper pan with oil before the head
                                chef stepped to the stove.

DASHES

Use the dash, or a pair of dashes, to indicate sudden changes in tone or thought or to interrupt a sentence's structure to add information--either in the middle or at the end of a sentence.

1.         (definition) Although the emphasis at the school was mainly language--speaking,
                        reading, writing--the lessons always began with an exercise in politeness.

2.        (appositive) Two of the strongest animals in the jungle are vegetarians--the elephant and
                        the gorilla.

3.         (contrast) Tampering with time brought most of the house tumbling down, and it was
                        this that made Einstein's work so important--and controversial.

4.         (emphasizing an aside) Television showed us the war. It showed us the war in a
                        way that was--if you chose to watch television, at least--unavoidable.