Quotation marks are a very familiar punctuation device, and we’d have a tough time surviving without them. As a famous writer once said, “Quotation marks allow us to identify what someone actually says, as opposed to simple statements being made by the writer.” Actually, I just made that quote up, but it illustrates one of the primary roles of quotation marks. The other is to denote when something is being lifted from another source.
There’s a third use for quotation marks, and it’s not well-understood. It’s to imply that something isn’t really what you’re presenting it as. For example, if I wrote that a necklace was made from “silver” or “real” silver, I’m implying that it’s actually an imitation. If I said that a particular political candidate is “smart,” I’m suggesting that she’s dumber than that proverbial box of rocks.