Adverbs at work: slow and slowly

A reader asks:

Can you cover the proper use of fast and slow as adverbs? People often say, “drive slow.” Should it be “drive slowly”?

Both “slow” and “fast” can be either adjectives (a slow drip, a fast computer) or adverbs (The nervous student turned the knob slow. The car goes fast.) As adverbs, “slow” and “fast” describe how an action was taken.


“Slow,” however, can become “slowly.” (“Fastly” isn’t accepted as a standard form.) In formal writing, most would choose “slowly.” We must drive slowly to save the small amount of gasoline we have.

Bryan A. Garner in “A Dictionary of Modern American Usage” has great advice on “slow” versus “slowly”: “Though slowly is the more common adverb and is certainly correct, slow is often just as good in adverbial sense. … In deciding whether to use slow or slowly, let rhythm and euphony be your guides.”

In fact, two idioms illustrate that point: My watch runs slow. Take it slow. Neither of those would sound right to us if we changed “slow” to “slowly.”

See American Heritage Book of English Usage and the Columbia Guide to Standard American English entries on slow.

Note that the comparative and superlative forms work too: slower and slowest, more slowly and most slowly.

So whether your mother tells you to “drive slower” or to “drive more slowly,” you should listen to her and slow down.

This article was originally posted by the Raleigh News & Observer, a subsidiary of The McClatchy Co.; is posted here to provide continuity; and is copyright © 2011 The News & Observer Publishing Company, which reserves the right to remove this post.