TAKE A LOOK: -, – and — all look more or less the same. But the hyphen, en dash and em dash behave differently.
A hyphen is placed between co-joined parts of a word (see what I did there?). An en dash is used to signify a change of direction in a sentence – such as this one here. En dashes – like these two – travel in pairs when they indicate an aside in the middle of a sentence. They always take a space either side of them.
Em dashes—and here are a couple—perform the same function as en dashes, except you don’t leave a space either side of them.
Hyphens are always used in compound adjectives, which are formed when a noun is appended before a verb. So it’s used by house-building companies, throat-soothing lozenges and high-minded pedants.
