What exactly is a flat adverb? [duplicate]
I know that a flat adverb is an adverb that has the same form as its related adjective, but does that mean any adverb without the -ly suffix is grammatically correct? For instance, if I said I am “extreme angry,” is that the same as saying I am “extremely angry”? Or is saying that it is “dangerous hot outside” the same as saying it is “dangerously hot outside”? I realize that flat adverbs are less common than they used to be, but that doesn’t change the question: Are flat adverbs always formed from words, namely adjectives, missing the -ly suffix?
Thank you
PS: This is what prompted my question:
“Flat adverbs used to be much more common than they are today. For example, in Robinson Crusoe, Daniel Defoe writes of weather that is "violent hot." Samuel Pepys wrote in his famous diary of being "horrid angry." But most of these adverbs have long since been abandoned.”
Bolded words are my emphasis.
You can't just willy-nilly remove the suffix and make it a flat adverb. Well, technically you can, but it's going to sound awful bad to a lot of people. See what I did there?
Some adverbs are flat by "standard" usage.
Take it slow contains slow as a flat adverb, and sounds perfectly normal, thought take it slowly also sounds fine.
Fast never uses an -ly form. They moved fastly wouldn't be correct to anyone's ears. Fast is an inherently flat adverb.
Edit: However, it has become common to use adjectives in an adverbial way on the Internet. Aside from the Bostonian "wicked awesome", I see more and more social media posts using flat adverb-type wording. So, given the way English works, I'd say in a few years you'll be able to just flatten any adverb you like and people will find it relatively normal.
1) No, you cannot just use any adjective as an adverb. Extreme angry and dangerous hot are grammatically incorrect. As Jesse Williams says, "wicked awesome," may be a colloquial phrase from Boston, but that does not make it correct.
Flat adverbs can be a bit confusing as the conventions change. In general, flat adverbs that "swing both ways" are considered conversational or informal (real, slow, quick, etc).
2) Are flat adverbs always formed from adjectives "missing" the -ly suffix? Yes. That pretty much defines a flat adverb. It is an adverb that is also an adjective.
One of the confusing points about flat adverbs is that some words are basically always flat adverbs, some words are grammatically acceptable as flat adverbs, and some words are used colloquially as flat adverbs but are grammatically incorrect. Some situations blur the lines between these categories.
For example, fast is a flat adverb. We don't really say, "He walked fastly down the street." We can say, "He walked fast," or we can use some other adverb like rapidly, quickly or hastily. Fast is pretty much always a flat adverb, but you might find some uses of fastly in very old, obscure texts.
Slow is a word that has come to be accepted as a flat adverb. I read about a survey in which a majority of native English speakers considered "walk slow" to be unacceptable in the 1960s. However, in 2015, the majority accepted the phrase as grammatically correct (https://bridgingtheunbridgeable.com/usage-polls/). Note that slow is not always appropriate for use as an adverb. For example, you can write, "He walks slow," but you cannot correctly write, "He slow walks." You can write, "He slowly walks." Some have also pointed out the slight difference in meaning as one puts more emphasis on the adverb. "Walk slow" has a different feeling than "slowly walk."
This brings up another point on the appropriateness of flat adverbs. Some were once considered grammatically incorrect, but are not accepted in conversation or informal writing. "That looks real nice," may be accepted in conversation, but it is grammatically incorrect. "Walk slow" is more accepted, but you will sound like a bit of a rube if you say, "He drove slow down the street." What's worse? "He drove real slow down that busy street." That said, slow is accepted as a grammatically correct flat adverb, at least in informal writing or conversation, while real has not been accepted. It can be really confusing. Using a random adjective as an adverb is usually not correct, but it has a conversational feeling, like wicked cool or straight fucked. http://www.learnersdictionary.com/qa/Slow-Slowly-and-Flat-Adverbs
Another strange phenomenon is that flat adverbs were stylistically common for a while (early 18th century), and then they went out of style (late 19th century). Lately, they have been coming back into style in slang and conversation. Supposedly the term flat adverb was coined "in 1871 by John Earle, and even in that time they were viewed as "rustic and poetic" because they were "archaic"." https://en.wikipedia.org/wiki/Flat_adverb#cite_note-:1-16
In recent years, flat adverbs often come into vernacular conversationally from regional dialects or colloquialisms and later make their way into the mainstream. The internet, slang, and local dialects seem to be bringing more flat adverbs into acceptance. It can be mad confusing.