Punctuation and the Colon Help (page 2)

Colon Help

Both the colon and the semicolon can be used to build better, more interesting sentences. Good writers use these marks of punctuation to build memorable sentences. You know that you can use a semicolon to join two sentences to create a compound sentence when the two thoughts are closely related. On the other hand, you can use a colon when the first sentence creates an expectation in the reader that the second sentence will explain, illustrate, or fulfill the idea stated in the first sentence.

We've quoted John F. Kennedy; now fast-forward to Barack Obama's one line in his speech to the Democratic Convention, August 2008.

That's the true genius of America: America can change. Our union can be perfected. What we've already achieved gives us hope for what we can and must achieve tomorrow.

What does the colon accomplish in the first sentence? It clearly helps fulfill the expectation set in the first half of the sentence. What is the true genius of America? The answer follows the colon.

Here is another example of building ideas with punctuation from Barack Obama's acceptance speech in Chicago:

And for the sake of our economy, our security, and the future of our planet, I will set a clear goal as President: In ten years, we will finally end our dependence on oil from the Middle East.

What is the clear goal? The answer follows the colon.

After all the rules you've learned about various punctuation marks, you'll find the colon has very few. However, the colon offers the writer an opportunity for variety in sentence structure; consequently, it is a valuable addition to your writing power.

How to Use the Colon

1. Use a colon to introduce a list, as in the following sentence.

Assemble these ingredients for the cake: flour, sugar, baking powder, eggs, and vanilla.

2. Use a colon to introduce an explanation.

I have a motto about getting distasteful chores done fast: Make a list of the chores, put a limit on the time you will devote to the work, and start with the one you dislike the most.

When you use the colon correctly, the information that comes before the colon should be able to stand alone as a complete thought. Otherwise, you should not use a colon.

Incorrect: I ordered: potatoes, sugar, flour, eggs, and coffee.

Also, if the information that comes after the colon is a complete sentence (as in the first example for Rule 2), use a capital letter, as you would normally do in the beginning of a sentence.

Look at another example:

Children will take up activities if you supply some good ideas for play: Color and paint in an art center that you create, cut up used holiday cards and paste them as stickers, choose a costume from a costume box and create a play or dance routine.

NOTE: In the preceding sentence, the words before the colon could stand alone as a sentence. What would happen if you added the words which are after good ideas for play?

Children will take up activities if you supply some good ideas for play which are: color and paint in an art center that you create, cut up used holiday cards to paste as stickers, choose a costume from a costume box and create a play or dance routine.

You now see a common colon error. To avoid it, do not use a verb before the colon—in this case the verb is the word are.

Practice

Read the following paragraphs. Use all that you have learned about punctuation to correct the sentences. The sentences are numbered for clarity in the Answer Key.

Paragraph 1

1. High school students know all about the Hubble Space Telescope in fact they can't even remember a time when it wasn't there. 2. The Hubble was launched in 1990 and it has already outlived its expected 15-year life span in addition it has seen its fifth and final repair mission.

Paragraph 2

1. Hubble entered our lives in the 1990s its advent paralleled the enormous growth in access to the Internet as a result everyone's computer was capable of bringing the magnificent images of the universe up close. 2. However Hubble is much more than pretty pictures interestingly it has generated more research papers than any other scientific instrument. 3. Before Hubble astrophysicists could never agree on the age of the universe some had said it was 10 billion years old while others had said 20 billion. 4. Hubble did the correct calculations our universe was born 14 billion years ago. 5. Hubble accomplishments include the following measuring the age of the universe, discovering that the Milky Way has a massive black hole in its center, and uncovering the role of "dark energy" in an expanding universe.

Answers