When I first started doing the One Year Adventure Novel curriculum, I was flabbergasted to see that Mr. S (wise as he was) wouldn't let me use adverbs and adjectives – at least, not many of them.
As time has passed, I've come to understand why it's not advisable to use them. Though it seems at first to be a direct attack against description, avoiding the two really is a good way to strengthen your novel.
As a quick review, adverbs are words that modify verbs, and adjectives modify nouns. Thus, in the green fish, “green” is the adjective. It modifies the noun; it makes the fish green. In he laughed sarcastically, sarcastically is the adverb; it modifies the laugh, making it a sarcastic laugh.
So why shouldn't you use them?
Because, while they are useful, they often clutter prose. The two things that drive your prose are your verbs and your nouns. Those must be as good as they can be. Too often we rely on adverbs and adjectives to help “move” our prose along, making the verbs and nouns weak.
Take these two examples:
The colorful bird flew gracefully downwards.
The brown-striped cat walked stealthily down the hall.
Both of these examples rely on both adjectives and adverbs to make the prose move. That makes them a prime example of what not to do.
I said earlier that nouns and adverbs drive your prose. Let's strip these two sentences of everything except those “driving” forces.
The bird flew downwards.
The cat walked down the hall.
Not too impressive, are they? That's because they relied on their modifiers to get them moving. They're rather dull and unspecific.
So how do we fix it? We start by changing the verbs and nouns themselves, compacting the most specific information as possible into one word. Let's change colorful bird into parrot, and brown-striped cat into tabby. Not only does it condense prose, but in the case of the first sentence, it makes the description more specific, not less!
Now that we've dealt with the adjectives, take a look at the adverbs. Flew gracefully can be changed to glided – again, this gives more information than the original sentence – and walked stealthily can be changed to snaked. (This isn't the only word you could use, however. Slunk, padded, and ghosted are all words that could have been used as well.)
All right, so we've strengthened our nouns and verbs and gotten rid of the adjectives, let's put everything back into our “stripped” sentences.
The parrot glided downwards.
The tabby snaked down the hall.
You can see that the prose is now much more vivid and descriptive than our original examples. And there isn't a single adverb or adjective!
Getting rid of adjectives and adverbs helps your prose immensely. Normally they cloak weak verbs and nouns, but once those are stripped away, the weaknesses are evident to see and can be modified accordingly. (Pun intended. Or was that pun too vague for anyone to get it?)
Before I move on, I must note one exception to this rule: the word “said”. As I've said before, “said” is essentially invisible as a dialogue tag. No one notices it when the author writes “he said” simply because it's so common. Dialogue tags are merely a means to an end; they indicate who is speaking. Now, if you wrote “expostulated” or “interjected” as a dialogue tag, it tends to jerk your reader out of the dialogue.
Thus, rather than use a “specific” dialogue tag, I often use “said [adverb]”. He said dryly is more interesting and less noticeable (in my own humble opinion) than he deadpanned, even though the latter is more specific.
Now, there is one problem that may come out of this: a paranoid extermination of adverbs and adjectives altogether. This is one thing I've witnessed myself. In fact, when I let a OYANer critique my stuff, I give this disclaimer: “All of those adverbs are there on purpose.”
Because, as long as your verbs and nouns are strong, adverbs and adjectives can strengthen your prose even more.
Take this passage from Joseph Conrad's Heart of Darkness, for instance.
“The wastes of his weary brain were haunted by shadowy images now—images of wealth and fame revolving obsequiously round his unextinguishable gift of noble and lofty expression.”
Take a look at those verbs and nouns: haunted, images, revolving, gift, expression. Those are powerful, specific words. But look what happens when you take out all of the adverbs and adjectives.
The wastes of his brain were haunted by images now—images of wealth and fame revolving round his gift of expression.
Not half as powerful, is it? The adjectives as well as the nouns, adverbs as well as the verbs; they were all powerful. Weary, shadowy, obsequiously, unextinguishable, noble, lofty; those modifiers made the prose sweeping.
This illustrates my final point: adverbs and adjectives can actually help prose when used right. That's why wholesale extermination of modifiers can be detrimental to your novel.
In fact, you could say that the entire point of this post is this: adverbs and adjectives, when used with a strong verb or noun, strengthen the prose; but when used with a weak verb or noun, they clutter the prose.
The key is to make sure your central, essential words – your nouns and adverbs – are powerhouses. Once you've achieved that, your prose will be a powerhouse too – and sweep your reader off of their feet.