1.
When we are very young, we tend to regard the ability to use a colon much as a budding pianist regards the ability to play with crossed hands: many of us, when we are older, regard it as a proof of literary skill, maturity, even of sophistication; and many; whether young, not so young, or old, employ it gauchely, haphazardly, or at best inconsistently.
Eric Partridge
3.
A dash derives from "to dash," to shatter, strike violently, to throw suddenly or violently, hence to throw carelessly in or on, hence to write carelessly or suddenly, to add or insert suddenly or carelessly to or in the page. "To dash" comes from Middle English daschen, itself probably from Scandinavian-compare Danish daske, to beat, to strike. Ultimately the word is-rather obviously-echoic.
Eric Partridge
4.
Like italics and hyphens, quotation marks are to be used as sparingly as possible. They should light the way, not darken it.
Eric Partridge
