There have been several claims about what the longest sentence in English is. They range from over a thousand words (1,288 in Faulkner’s Absalom! Absalom!) to nearly 14,000 (13,955 in Jonathon Coe’s The Rotter’s Club). Even though Coe’s apparently got the record nailed down tight until new sentence technology is discovered, 1,288 is freakin’ long sentence. Especially when most sentences range between 10 and 20 words with outliers on both sides.
The Oxford Guide to Plain English recommends 15-20 word average sentences because as the author, Martin Cutts, explains, “More people fear snakes than full stops, so they recoil when a long sentence comes hissing across the page.”
Jyoti Sanyal’s Indlish has this to say on the subject: “Based on several studies, press associations in the USA have laid down a readability table. Their survey shows readers find sentences of 8 words or less very easy to read; 11 words, easy; 14 words fairly easy; 17 words standard; 21 words fairly difficult; 25 words difficult and 29 words or more, very difficult.”
Sentence length and ease of reading
- 8 words or less: very easy
- 11 words: easy
- 14 words: fairly easy
- 17 words: standard
- 21 words: fairly difficult
- 25 words: difficult
- 29+ words: very difficult
While there’s evidence that the average sentence length has shrunk 75% in the last 500 years – it wasn’t uncommon to see 70+ word sentences in the 1600s – that doesn’t necessarily mean it’s a good idea (or good writing) to go for the long sentence. The reason for that has to do with readability. There’s evidence that the average person reading a 14 word sentence will pick up +90% of what they’re reading; that number drops to less than 10% at 43 words.
All this sentence length and reading comprehension stuff is something that’s been pinging around in my head ever since I wrote that post on words back in June. The gist of that post was understanding average vocabulary size with a brief foray into reading levels in prose and why writing to a 7th grade level wasn’t necessarily a bad thing. While that post spent more time with the number of unique words in a book, it touched on the idea of sentence length impacting readability and that idea stuck in my craw. After all, even a short sentence filled with words like fustian, byzantine, and polyglot can make a minefield for some people:
The polyglot’s mind was a byzantine mass of competing ideas and definitions that led to her fustian speech.
Okay, so at 18 words that was slightly over the standard sentence length, but not so outside the norm that it should be hard to parse. On the other hand, most people don’t regularly use words like polyglot, byzantine, and fustian, so those will be speed bumps on the superhighway to comprehension. Other than that, there’s nothing untoward about the sentence. A simple parsing, even accounting for the odd word choice, should reveal she has a whole whack of ideas and definitions and that does something bad to the way she speaks. If you want to go full information density on it, we can also assume she’s probably smart since she knows multiple languages, but her thoughts are jumbled since she sometimes gets lost juggling all those languages and that reflects in the way she talks. Basically it’s an excuse for what seems like pompous oratory.
Parsing is the key element here. While there can be multiple types of sentences – declarative, interrogative, exclamative, and imperative – all sentences come down one key thing: relating words into a complete, coherent idea. Or, if you want to get all fancy with it, according to dictionary.com, a sentence is “a grammatical unit of one or more words that expresses an independent statement, question, request, command, exclamation, etc, and that typically has a subject as well as a predicate, as in John is here. or Is John here?”
So, really, a sentence is a bunch of words meant to convey a singular idea, no matter how complicated that idea might be. The kicker is, in order to understand the idea, you have to get through the sentence. That usually entails finding space in your head to store the words and brain CPU time to parse and process the words. All of this has to happen in the background as you’re reading and, in some cases, even moving onto the next sentence.
And you thought you weren’t smart. Shame on you. Even reading this post is requiring you to brain and brain hard.
By the way, if you’re thinking you’re going to break Coe’s longest sentence record, go for it. According to linguists, there is no functional top end in how long a sentence can be in English. Because of the way the language is structured, it’s possible to keep adding recursion (He said that she said that her grandmother said that Cthulhu said that guy over there did something…) or subordinate clauses or semi-colons or iterations or enumerations until the end of time. Even with just enumerations, it’s theoretically possible to write an endless sentence: She started counting to herself, never intending to stop: One, two, three, four, five, six… That sentence will only end when she runs out of numbers and I have it on good authority that there are a lot of them.
Does all this mean you should never go full Coe and write two short-stories’ worth of words into one sentence? Not necessarily, just realize longer sentences are harder to parse and, therefore, less likely to engage your reader. 15-20 words should be enough to convey the message you need to get across with a sentence. If it takes longer than that, or if you find yourself going balls to the wall with recursion, subordinate clauses, and whatnot, you might want to consider breaking longer sentences into shorter sentences. After all, it doesn’t matter how good your ideas are if no one can load and parse them.
A quick addendum to this: As was pointed out in the comments, vary the length of your sentences. Shorter sentences read faster which allows you to speed up the pace; longer ones slow reading down, which allows a reader time to rest.
Just try to avoid the 1000+ word sentences. No one wants to read those.
What are your thoughts on sentence length? Leave me a comment.