By Nicholas Klacsanzky
Many students whom I help with studying tend to make the same set of punctuation mistakes. What I’m talking about are dashes: the em dash, the en dash, and the hyphen. Although possessing completely different functions, these marks are often misused. So, to fix this “punctuational” injustice, I’ve prepared a short but useful post.
This one is easy to understand, so it often puzzles me how anyone can forget it; the en dash is used to mark any kind of range between at least two objects. In other words, if you write about a period of time between two dates, or a distance between cities, the en dash is your friend. Possible examples are, “the March–May newspaper subscription,” “9–11 grade students,” “Berlin–Krakow train,” “pages 341–347,” and so on. You should also use the en dash to connect a prefix to a proper open compound, like in “pre–war times.”
The most common use of the em dash is to insert an additional thought to a sentence (so it’s close to what parentheses do). Another use of the em dash is to substitute a missing word—for example, when there is no need in repeating the same word over and over again (in a list, for instance), you may simply use the em dash instead of the repeated word; you can also use em dashes to mark points in bullet lists. Two em dashes in a row (——) can be also used to mark interrupted speech.
Hyphens are inserted between two different words, that when together, form a new concept, or work together as a joint modifier. For example, “toll-free,” “drive-in,” “two-thirds,” “built-in,” and so on.
These are the basic rules, but they are used the most often. As you can see, there is nothing difficult about dashes and hyphens.