Sentence Length

Bring back your readers with sentences that are the perfect length.

Bonnie Mills, Writing for
4-minute read
Episode #827
The Quick And Dirty

An average sentence length of 30 to 40 words is fine, but you want to be sure you use a variety of sentence lengths to avoid boring your readers. Also make sure you don't have more than one main point per sentence.

My dad has a memorable poster in his bathroom: a diagram of a ridiculously long sentence by Marcel Proust. It’s from his masterpiece, "À la recherche du temps perdu ("Remembrance of Things Past," also translated as "In Search of Lost Time"), and it starts like this: 

“Their honor precarious, their liberty provisional, lasting only until the discovery of their crime; their position unstable....” 

Blah, blah, blah. I’ve examined it numerous times over the last two decades, but I’ve yet to finish wading through all 958 words. At 150 words longer than this entire column, the sentence is just unreadable. Believe me, I’ve tried to stick with it till the end, but it’s impossible.

Sentence fragments

I have to applaud Proust for being able to keep everything straight in that sentence—because he sure used a lot of semicolonscommas, clauses, and other tricks to lengthen it. I guess French literary geniuses didn’t take advantage of copy editors back then. 

Well, I’m going to suck it up and be the first to trim that monstrous sentence. Here we go. “Their honor precarious, their sentence too long.” [Period.] Oh no! Now my honor is precarious. My crime has been discovered: Those seven words are an incomplete sentence, also known as a sentence fragment. It has no verb. Do you think Proust ever wrote one of those? Nah. Bet not.

All this Proust talk is making me hungry for a madeleine, a small shell-shaped cake that had a starring role in "In Search of Lost Time." I think we should go in search of the perfect length for a sentence. The long and the short of it is this: If you stuff in too many things, you’ll get an overly long sentence; if you leave out a subject, verb, or necessary object, you’ll be stuck with a fragment.

The best way to cut down a long sentence is to figure out your main points.

Finding the proper length

Proust’s enormous sentence is an anomaly, but long sentences certainly haven’t disappeared. These days, plenty of meandering sentences roam through manuscripts. These behemoths suffer from too many "which," "that" and "who" clauses; an overabundance of commas and semicolons; at least a few cases of "and" or "but"; and several sets of em dashes. When your readers try to wade through such a sentence, they become lost amid clauses and commas, and they give up before the sentence is finished.

Your readers are following a path you’ve laid out for them. Don’t try to be a turbo guide and make them traipse along too many side streets. They’ll become exhausted and collapse. On the other hand, you don’t want to whisk readers along too quickly with too many incomplete sentences either. They’ll feel as if they’ve missed something. Fragments call attention to themselves; you don't need to avoid them at all costs, but if you overdo them, you’ll annoy your readers.

Your tour group doesn’t like feeling fatigued and frustrated, so you have to morph into a better tour guide. Plan your excursion carefully and plot out a manageable route. Your trip’s core should consist mostly of medium-sized sentences. Budget for a few windy detours that point out some fascinating facts, and make a couple of quick stops in the sentence fragment department to keep participants alert. Whatever you do, don’t fall into a monotonous medium-sized rhythm that anesthetizes your readers.

Most sentences should contain no more than 30 or 40 words.

“Medium-sized” means minuscule by Proust’s standards. Most sentences should have no more than 30 or 40 words. Your readers just don’t have a very long attention span, and their feet tire easily. Back in Proust’s day, email, TV, and social media didn’t exist to distract the public, so I guess readers were a hardier bunch. They probably perambulated around town a bit more, too.

Finding and fixing long sentences

If you've resolved to tame your inner Proust, I have a couple of suggestions.

First, although Microsoft Word's Grammar Checker isn't known for its helpfulness, it does notice long sentences and sentence fragments. If Grammar Checker has filled your screen with squiggly lines, pay attention. It won’t fix your sentences, but it will help you identify them.

Second, if you read your sentence but can’t remember what happened at the beginning, the sentence is too long. Have a madeleine while you rest and refresh your memory. After your tummy is full, you can chop up your sentence into manageable bits.

The best way to cut down a super-long sentence is to figure out your main points. (When you investigate, you'll often find that your long sentences have two or three main points crammed into them.) Break that sentence apart, and highlight each main point with its own medium-sized sentence. Then deal with your leftover crumbs. Once you’ve mapped everything to its proper location on your tour, make sure your transitions work and everything fits together seamlessly. Then you can put your feet up and rest.

A version of this article originally appeared in "Writer's Digest."

Image courtesy of Shutterstock.

About the Author

Bonnie Mills, Writing for Grammar Girl

Bonnie Mills has been a copyeditor since 1996.