How to Use Dashes

How to Use Dashes

Not all dashes are the same. There are three distinct kinds of dashes, each of which has different uses: hyphens, en dashes, and em dashes.

The first, and likely most familiar, is the hyphen (-). This is a short dash which has a number of uses, the most common of which is to link related words into a compound word (e.g. “sugar-free”).

When to use a hyphen is not always clear. Traditionally, a hyphen was used to create a compound word made of two otherwise unrelated words. Yet English is continually changing and hyphenating words is becoming less and less common. Some words and phrases, such as X-ray or brother-in-law will always use hyphens. However, many modern words directly become full compound words without a hyphen, such as spacebar.

Hyphens should always be used when spelling out numbers. They are also used to provide an interval, such as with time or quantity.

Twenty-one, forty-five
The Hundred Years' War (1337-1453)
Control group of 20-30 individuals

Hyphens are also used when adding a prefix to certain words, especially proper nouns. (Tip: this is especially used for historical periods.) Examples include pre-Renaissance and post-Napoleonic. There are a few exceptions such as postmodern, which is a specific term that can be written either with or without a hyphen (postmodern vs. post-modern)

Some phrases, like well known or high class do not normally use hyphens. However, if this kind of term is used as an adjective (usually placed before the noun it is describing) then a hyphen is used to clarify the description.

The teacher was very well read.
The well-read teacher was...

A special case of this kind of adjective phrase is when two such phrases are used in the same sentence that have a word in common, such as in the example below.

The list of first-rate and second-rate institutions...
The list of first- and second-rate institutions...

As shown above, when there is a word in common, that word can be omitted and the trailing hyphen signifies that it shares the second word of the following phrase. However, the first sentence is perfectly acceptable and “rate” does not have to be dropped. If you do choose to omit the common word, you must ensure that there is still a hyphen at end of the first word (“first-“).

The en dash (–) is slightly longer than the hyphen. Based on the size of the letter “n,” it too has a number of uses. En dashes can be used in place of a hyphen for ranges of numbers:

The Hundred Years' War (1337–1453)

Whether a hyphen or en dash is used in this case is largely dependent upon the writing and citation style used for the course or paper you are working on. APA uses en dashes for numerical ranges, but some other styles prefer to use a hyphen. Double check what style you should be following and ensure you adhere to its guidelines. Also make sure that you are consistent within your own paper. If for some reason your style guide, assignment, or professor is not specific about which to use, choose one and use it throughout your paper; do not switch back and forth.

En dashes can also be used in place of parentheses or to bridge sentences. In this case, a space should precede and follow the en dash.

The Allied leaders – Roosevelt, Churchill, and Stalin – met at Yalta.
He walked towards her – she stopped.

Typically, parenthetical phrases and bridges are done using em dashes, discussed in the next tab. Again, this will depend upon the style you are following, but above all, be consistent!

Based on the size of the letter “M,” the em (—) dash is the longest of the three dashes. The primary use of the em dash is to separate phrases within a sentence that could either be surrounded by parenthesis or separated by a comma or period. The em dash is preferable in these situations when the flow of the sentence would be disrupted by the other punctuation or when extra emphasis is desired. When used in this way, no spaces are put around on em dash. It is placed directly next to the words it is linking.

The Allied leaders—Roosevelt, Churchill, and Stalin—met at Yalta.
He walked towards her—she stopped.

The first example is a parenthetical statement, in which the middle clause (Roosevelt, Churchill, and Stalin) are not grammatically necessary for the sentence. The sentence could have been written with parentheses, as shown below.

The Allied leaders (Roosevelt, Churchill, and Stalin) met at Yalta.

The above sentence is correct and acceptable, but reads very differently. Parentheses usually denote extra or clarifying information which some readers might be inclined to skim over. However, using the em dash allows for the same sentence construction but the parenthetical statement is more solid in the sentence.

The second use of the em dash is when you want to link two clauses that would otherwise be separated by a colon, comma, or period. These two clauses should be closely related—either by subject, time, cause, or contrast—which would make the use of a period too strong and a comma too weak. (In some situations such as this, the link might be better made with a semicolon.)

1789—a year of great change.
The Ottomans had conquered all the surrounding 
lands—Constantinople prepared for siege.

The em dash can be very useful in both these regards, but be careful not to overuse it. With the first form of use, too many parenthetical statements can make your writing confusing to a reader and distract from your main points. With the second use, the bridge can add needed emphasis or linkage, but too many such connectors can make your writing too choppy or overly dramatic—neither of which is something you want.

Lastly, an alternate use for the em dash is to denote the source of a quotation, where it is placed between the end of the quote (with a space) and the source (without a space). See below.

"Ask not what your country can do for you—ask what you 
can do for your country.” —John F. Kennedy

How to Use Dashes in Your Writing | WriteWell Bros.

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