I don't understand hyphens

Seriously. I was taught (in the pre-computer era) Oxford hyphen usage: you use one followed by a space when it’s punctuation, and you use one without spaces in hyphenated words. Latterly, I have come to understand that there are emdashes and all sorts of other types of hyphen that I have little or no knowledge of the usage of (much less how you make one with a keyboard.)

I suppose I’m suppose to have an actual question here, so what types exist and what are they for?

I think—though I’m sure the experts will soon be chiming in—that there has always been a distinction between the hyphen, the en-dash, and the em-dash (and perhaps the minus sign) in printing/typesetting, but in the days of typewriters, you had to use the “hyphen” character for all three of these things. Nowadays you can distinguish among these on a computer.

For example, in the previous sentence, I used em-dashes to set off “though I’m sure the experts will soon be chiming in.” On a typewriter, I would have used a double hyphen–like this–or maybe a spaced hyphen - like this - for this purpose.

I think—but again, correct me if I’m wrong—that a hyphen proper only occurs within a word (a hyphenated word, or a long word broken up at the end of a line of text).

There are three variants, hyphens, en-dashes, and em-dashes. A manual of style will give “rules” for their use, but remember that style is important only in a formal final product. What you do when typing your manuscript or communicating can be very different and totally idiosyncratic. In the olden days, a an editor would mark up a manuscript to indicate what went into the final typeset copy.

There are zillions of possible uses for them, so I’m going to pick out a few of the most important, as give in the Chicago Manual of Style, 13th ed.

used in compound words: court-martial; clearing-house

used to break words at the end of lines in justified text:

But writers who find themselves under-
lining frequently for emphasis may consider…

em dash (used as *the *dash in the book)
used to denote a sudden break in thought: Will he—can he—obtain the necessary signatures?

en dash; one half the length of an em dash
used in dates: 1968–1972; May–June 1967
used in compound adjectives: New York–London flight; post–Civil War period
used for sections: see sections 5.82–96
used for page numbers: 334–402

There are also 2-em dashes and 3-em dashes used in specialized situations like missing words: A vessel which left the ——— in July …

The Chicago manual advises never to use spaces around dashes (except for an odd nitpick or two). Other sources would tell you to use spaces around an em dash. That’s pure style, not a rule.

I have no idea how your browser will parse the symbols, but I used real em and en dashes instead of hyphens where appropriate.

Here’s my answer for what it’s worth.

A hyphen connects words to make a sort of new word when used to describe another word, for example:

not-so-funny joke

A hyphen also connects words that are hyphenated when divided by a line break, for example:


A dash is an easy and dramatic way of making a break in a sentence, for example:

He told a joke–but nobody laughed.

Note I used two hyphens to make a dash. That’s because a hyphen is an “en” dash. It is the width of the lower-case letter n. A dash is an “em” dash, which is the width of the letter “m.” If you don’t have an em dash handy, like in plain type here, you can use two en dashes instead. Some people use a hyphen with a space on each side too - like that.

I can’t think of any other hyphen or dash uses–can anyone else?

Technically, no. A hyphen is shorter than an en dash, and it also may be at a different height depending on font, Calibri, e.g.

I tend to use doubles because I started on a typewriter. Word changes them automagically for you, which I find rather annoying. What are they for? I like to reserve them for breaks in sentences that are rather abrupt. It tells the reader, “Hey, I’m going to detract from the main part of the sentence to give you some info about what I was just talking about.” I use commas for every other kind of break where they are typically used.


I’m a fan of 700 megabyte movie disks–the old school ones that you could play on a player.
I’m a fan of 700 megabyte movie disks, the old school ones that you could play on a player.

Both are acceptable, but for my own use, the first isn’t just a break in the sentence, it’s a break that comes before content that is an explanation of previous content. If you are reading pages and pages of text, I think it is easier to add these kinds of devices so the reader doesn’t have to do as much mind work.


A well-known rule. Typical use of hyphen: two words that describe the following word.

A rule that’s well known in these parts. No hyphen because the two words stand alone (“rule” is separated from them by “that”).

An easily understood rule. No hyphen because one of the words is an adverb ending in “-ly.”

I just want to point out that they’re an utterly stupid addition to punctuation. Commas, apostrophes, quotation marks, colons, semicolons, the various terminal punctuation all have useful functions. Nothing em or endashes do can’t be done by a hyphen and vice versa.

Last time this topic came up, I
[quoted Edgar Allan Poe on the dash.]
(http://www.eapoe.org/works/misc/mar0248.htm) His views on composition and poetic effects are both informative and fun to read.

But why would you want to use a hyphen for a totally different function? Surely it would be more confusing to use the same punctuation mark for two different uses? Dashes are completely unrelated to hyphens.

Incidentally, modern usage — at least in the UK — is to use spaces either side of em dashes, as in this sentence.

Okay, but if so, what’s the difference in how you use them? Is a hyphen just for hyphenation but an en dash for connecting whole words?

I disagree. Only an em dash has the drama its use requires. Size matters.

And I would like to add to the other responses by stating that this is an utterly stupid post.

What is the downside to a punctuation mark that has a clearly defined purpose, distinct from the purpose of another one? What is the upside of having one punctuation mark that serves completely different purposes — particularly when the context in which it might appear would be similar (i.e., between words)?

I dunno. Is “I’ll clean the fo’c’sle’s floor this afternoon.” more confusing because it’s using apostrophes to demonstrate missing letters and possessiveness?

Can you tell at a glance which of 35-40°F, 35–40°F and 35—40°F is right and wrong? If someone uses the ‘wrong’ mark are they at risk of misinterpreting the sentence? I don’t think so.

If we only used one of them, we’d have the same level of clarity in our writing and our writing system would be just a tad simpler. It’s nothing more than a copyeditor’s shibboleth.

Actually, the best use is “35 to 40,” avoiding confusion with subtraction.

No, there’s a possibility of confusion between the two.

For instance:

He killed the man-eating shark.

He killed the man—eating shark.

You could just use two en dashes, but that’s harder to see and ugly and stupid. We put alot more thought into fonts—we can handle two kinds of dash thingies.

I was always taught that en dashes had spaces but em dashes don’t. If I’m substituting with hyphens, I use a single hyphen surrounded by spaces for an en dash and two hyphens without spaces for an em dash.

Did you mistype–or was I misinformed?
The thing I really find annoying is when words are joined with an en dash. In the very, very rare cases where such disambiguation is necessary, I prefer to use a slash (/).

Three of those are just special cases of “use for a range” (usually of numbers, but sometimes letters, like “A-Z”). I have a hard time seeing the distinction, though, between the use in compound adjectives and the use of the hyphen in compound words. The two usages both look the same and quack the same-- Why isn’t the en-dash used in compound adjectives not just a hyphen?

And what about the minus sign? Ought it to be regarded as the same character as one of the others (in which case, which one?), or is it yet another glyph which looks very similar but is distinct?

I think I found the problem.