Q: What’s happening to adverbs? Is the “ly” going to disappear completely from our language? I’m thinking particularly of “slow” and “slowly.”
A: No, I don’t think “ly” adverbs are disappearing, but it may seem that way from some of the signs (“DRIVE SLOW”), ad slogans (“Think Different”), and informal expressions (“hang tough”) that have been popular in recent decades.
In fact, adverbs without “ly” (they’re called simple or flat adverbs) were more common in the past, though they may be making a revival now from all the complaints that I hear about them.
Many adverbs, including “slow” and “slowly,” exist in both forms (with or without the tail, as Theodore M. Bernstein puts it in The Careful Writer). Authorities on grammar and usage generally recommend the ones with the tail in formal writing, but there are many exceptions.
No one would complain about phrases like “sitting pretty” or “come close.” And a lot of tail-less oldies are still going strong (“fast,” for example, has been an adverb since around 900).
Here’s some history. We’ve had adverbs with and without the “ly” (or archaic versions of it) since Anglo-Saxon days. In Old English, adverbs were usually formed by adding “lice” or “e” at the end of adjectives.
Over the years, the “lice” adverbs evolved into the modern “ly” ones and the adverbs with a final “e” lost their endings. In recent centuries, writers have tended to add “ly” to the end of the simple adverbs or to prefer the “ly” adverb when two versions existed.
Which brings us back to “slow” and “slowly.” The Oxford English Dictionary’s first published reference for “slowly” dates from around 897 while the OED’s first citation for “slow” as an adverb is from around 1500.
Both adverbs are legit, and both have long histories, but be aware that sticklers consider “slow” a second-class citizen, good only for informal speech or writing.