Semi-colons and colons are less frequently used punctuation marks than the comma and terminal punctuation. However, semi-colons and colons can improve the structure and flow of writing when used correctly. Used incorrectly a semi-colon or colon can confuse readers, impede the flow of the work, and decrease the credibility of the author.
Learning how to use semi-colons and colons correctly is essential to good grammar and more sophisticated writing.
Is a Semi-Colon Like a Comma?
A semi-colon is like a comma in four ways:
- A semi-colon contains a comma as the lower half of the actual punctuation mark (;).
- Both semi-colons and commas create a pause in a sentence.
- Both punctuation marks appear in the middle of sentences.
- Semi-colons and colons can separate items in a list.
Despite the similarities there are important differences between the two punctuation marks.
How are Semi-Colons and Commas Different?
While both semi-colons and commas create pauses within a sentence, when reading aloud a reader should pause for longer at a semi-colon than a comma. (Two beats versus one beat.)
Whereas commas can set off appositives and interjections and separate dependent clauses, a semi-colon is used to separate independent clauses. Below are examples of sentences using semi-colons in places where a comma could not be used:
- She hit her knee in disbelief; Margot couldn’t believe her printer had jammed again.
- “Well since it’s on sale, I’ll buy it,” Kevin replied; he handed three crisp five dollar bills to the sales clerk.
- The sky faded to a dull gray blue; the approaching storm thundered imminently.
What Does a Colon Do?
Colons only have one function: a colon introduces. A colon can introduce several things in a sentence:
- A list (like the colons in this article do)
- A quote from an outside source (don’t forget to cite the source to avoid plagiarism)
- A fact
It is important to note that however a colon is used, a colon cannot immediately follow a verb.
Below are examples of colons being used incorrectly:
- Becky’s dress is: red, blue, yellow and orange.
- The sky was several: colors, dusty pink, creamy orange, and steely blue.
- We wanted to visit the crown of the Statute of Liberty during our trip: seeing everything from up high is exhilarating.
In the first example the colon immediately follows a verb. To correct this grammatical mistake the sentence can be reworded. “Becky’s dress is patterned in flowers: red, blue, yellow and orange daisies.” By providing more detail the colon be used properly to introduce the list.
In the second example the colon is incorrectly placed because it is not immediately preceding the list of colors. Moving the colon to after the word “colors” instantly fixes this sentence and makes it grammatically correct.
In the third example the colon is separating two independent clauses. A semi-colon would be more appropriate in this example.
Why Use Semi-Colons and Colons?
When semi-colons and colons are used correctly they can add variety to a piece of writing by increasing variety of sentence structures and sentence lengths used, improve flow and readability by separating and introducing ideas as necessary, and increase the credibility of the author by showcasing the advanced grammar skills of the author.
