En dashes (whose lengths are the same as an “n”) are half the size of an em dash and slightly larger than a hyphen. Unlike em dashes, en dashes have quite specific times in which they may be used, and do not stand in for other punctuation.
Date and number ranges.
Standing in for the words “to,” “through,” “including,” and “up to” (but “to” more than anything else), en dashes are often used in showing ranges of numbers and portraying the movement of time.
Living circa 1340–1400, Geoffrey Chaucer did much in his 60 years to impact the next 600 years of English literature.
“I’ve read The Canterbury Tales 10–12 times” Katie bragged to Dr. Green, luxuriating in a sparkle in the professor’s eyes that she mistook to be awe.
If the first example had included the word “from” before the first date, it would not have needed an en dash, but would have rather read as “living from circa 1340 to 1400…” Thus, any time you introduce your numbers (And dates, in particular) with the word “from,” maintain the “to” that the en dash is replacing.
Likewise, if the second example had introduced the scale with the word “between,” the en dash would have to be replaced with “and,” making the sentence “I’ve read The Canterbury Tales between 10 and 12 times…” So, when ranges are introduced with the word “between,” ensure that you do not use an en dash.
Movement and scores.
Still standing in for the word “to,” en dashes can also be used to indicate things like athletic scores and travel.
Finishing with a final score of 3–10, my quiz team certainly learned the hard way what Katie McDonald had meant when she said that she knew Chaucer “better than all of you plebeians.”
The London-Canterbury route, although an easy drive today, was no little journey in the 14th century when pilgrims often made the trip on foot.
Complex compound adjectives.
Our final use for en dashes is found in simplifying sets of compound adjectives. Compound adjectives are simply those adjectives that contain multiple words, often with a hyphen. A “brightly-lit” room, or a “high school” sophomore. The need for an en dash arises when two of these compound adjectives are in use at once. (Please note that most academic style guides prefer the use of as few hyphens as needed, and as clear of language as possible so it is the rare sentence that will need to deal with multiple compound adjectives at once.)
We know that in the post–Middle English era of today, films and books contain plotlines that are ripped from earlier stories, but what we rarely realize is that there is a long history of this kind of “plot stealing,” extending all the way back to Shakespeare and Chaucer.
Because “Middle English” is a compound noun (but operating like an adjective here, in that it describes “era”), the en dash helps make sense of and separate the “post” that is also working to describe “era.”