Proper Use of a Dash
- Writers often confuse the em-dash with the hyphen and the en-dash. Em-dashes occur within sentences. En-dashes are used to indicate a range in numbers or link names which are not compound words. Hyphens are used to create compound words or to break a word at the end of a line for continuation on the next line. The em-dash is the length of a standard length "m" in most typesets, while the en-dash is the size of a letter "n." A good way to keep the en-dash and the em-dash straight is to remember the "n" connects while the "m" separates.
As a Colon
- Use a dash in less formal writing where a colon would normally be placed. This helps to emphasize. For example: "The children were asked to do three things---pick up their clothes, make their beds and find their backpacks."
- Use the dash in the place of parentheses when an emphasis is desired. Parentheses are often regarded as material that can be left out of a sentence. The dashes often include additional information that the writer feels the need to give a place of importance in the sentence structure. For example, "The trees---the one in front and the one in back---were cut down to make room for the new driveway."
- Use the dash at the beginning and end of a series. This eliminates confusion caused by too many commas. For example, "The dogs---Roscoe, Spike and Killer---loved to play in the mud."
- Use the dash to give identity to the subject. The dash essentially replaces such words as "in other words" and "that is." For example, the sentence "The girl who is waving her hand needs to go to the bathroom," becomes "The girl---the one waving her hand---needs to go to the bathroom."
- Dashes offset breaks in thought. For example, "The child would not take his medicine---even for a piece of candy." This usage of the dash can occur in the middle of a sentence, as well. For example, "The child refused---even when offered candy---to take his medicine."
When writing dialogue, the dash can also show a shift in tone. For example, "This is a very key issue---are you listening to me?"
The dash can also show an afterthought or a correction. For example, "I gave her the key to the house---at least, I think I did."
The dash also reveals an emphasized pause. For example, "She was embarrassed when she walked through the door---and into the men's rest room."
How to Make
- The em-dash is created in typing by hitting the minus key twice without spaces before or after. For example--just like that. On Microsoft Windows, an em-dash can be created by holding down the Alt key and typing 0151. In Microsoft Office applications, it can be created by using the combination of Ctrl-Alt-hyphen. On a Mac, the em-dash shortcut is Shift-Option-hyphen on most keyboard layouts.