Fixing Sentences Over 20 Words
The Readability Checker flags sentences over 20 words because long sentences are where readers most often lose the thread. Not every long sentence is a problem, but a page where many sentences run to 30 or 40 words is tiring to read, especially on a phone.
This guide shows the five shapes long sentences usually take, the right way to split each one, the false alarms to ignore, and how to bring the average down without turning your writing into a string of choppy fragments.
- Why long sentences cost readers
- The five shapes of a long sentence
- Finding the sentences worth fixing
- The fix, step by step
- Keeping variety: the mistake after the fix
- Long sentences you can leave alone
- Where long sentences hide on common sites
- Stopping long sentences at the drafting stage
- Questions and answers
Why long sentences cost readers
A reader has to hold the start of a sentence in mind until the end tells them how the pieces fit. In a short sentence that is easy. In a long one, especially where the main verb arrives late or several conditions stack up before the point, the reader has to keep many parts in the air at once. Some re-read. Others skim to the end and miss the condition that mattered.
Length alone is not the whole story. A 30-word sentence that moves in a straight line, subject then verb then detail, can be easy. A 22-word sentence that opens with two qualifications and hides the verb in the middle can be hard. That is why this guide sorts long sentences by shape, not only by word count.
Plain English guidance commonly suggests an average of about 15 to 20 words per sentence, with plenty of variation. The 20-word flag in the checker is a prompt to look, not a rule that every sentence must obey.
The five shapes of a long sentence
Most long sentences in web copy fall into one of these patterns. Each needs a slightly different fix.
| Shape | How to recognise it | Best fix |
|---|---|---|
| The chain | Clauses joined by "and", "but", "so" or "which", each adding a new idea | Full stop before each new idea |
| The late verb | A long opening phrase or condition before the subject and verb appear | Move the main clause to the front, or put the condition in its own sentence |
| The hidden list | Three or more items or steps packed into one sentence with commas | A bulleted or numbered list |
| The aside | Brackets, dashes or "which" clauses carrying background information | Give the aside its own sentence, or cut it |
| The padded sentence | One idea, but wrapped in phrases like "it is important to note that" | Delete the padding; the sentence may no longer need splitting |
The chain, before and after
Before (36 words): "We collect your old sofa when we deliver the new one, and we recycle it wherever we can, but there is a charge for collection if you order during a sale, which is shown at checkout."
After: "We collect your old sofa when we deliver the new one. We recycle it wherever we can. During sales there is a collection charge, shown at checkout."
The late verb, before and after
Before (32 words): "For customers who have purchased an annual plan before the price change and who wish to keep their existing rate for a further twelve months, renewal must be completed by 31 March."
After: "Bought an annual plan before the price change? You can keep your current rate for another year if you renew by 31 March."
The hidden list, before and after
Before (33 words): "To apply you will need your account number, a recent bill showing your address, photo identification such as a passport or driving licence, and the name and phone number of your current supplier."
After: "To apply you will need:"
- your account number
- a recent bill showing your address
- photo ID, such as a passport or driving licence
- your current supplier's name and phone number
The list is not shorter in words, but readers can tick items off, and the checker no longer sees one 33-word sentence.
Finding the sentences worth fixing
Run the page through the Readability Checker. It reports the average sentence length and flags individual sentences that need attention, including those over 20 words. On a long page that can be dozens of sentences, so triage them.
- Sort by length. Copy the flagged sentences into a spreadsheet with a word count beside each. Anything over about 35 words goes to the top; these do the most damage and are usually the easiest to split.
- Weight by position. A long sentence in the opening paragraph, a price explanation or an instruction matters more than one in a closing paragraph few people reach.
- Look for clusters. Three long sentences in a row are harder than three spread across a page. Fix clusters first.
False alarms
Readability tools find sentence ends by looking for full stops, question marks and exclamation marks. That leads to predictable mistakes:
- Bullet lists without full stops can be read as one enormous sentence running from the lead-in to the last bullet.
- Headings without punctuation may be joined to the first sentence below them.
- Abbreviations such as "e.g.", "approx." or "Ltd." can split one sentence into two, making the count look shorter than it is.
- URLs, email addresses and product codes may count as one word or several depending on the tool.
Check each flagged sentence on the page itself before rewriting it. If the "sentence" is a list the tool has merged, the fix is not to change your writing.
The fix, step by step
Step 1
Rank the flagged sentences by length
Run the page through the Readability Checker and copy every sentence it flags into a spreadsheet, with a column for word count and one for where on the page it sits. Sort longest first. Move sentences from the opening paragraph, prices, instructions and legal conditions to the top, because a reader who misunderstands those faces real consequences. This ranked list is your work queue, so you fix the worst cases before touching borderline ones.
Step 2
Clear out the false alarms
Look at each flagged sentence on the live page, not only in the report. Remove from your list any that are really bullet lists without full stops, headings merged with the next line, or strings of product codes and addresses. For lists the tool keeps merging, adding a full stop to each item or introducing the list with a complete sentence usually stops the miscount without changing how the page reads to people.
Step 3
Name the shape of each long sentence
For each sentence left on the list, decide which shape it is: a chain of joined clauses, a late verb after a long opening, a hidden list, an aside in brackets or dashes, or a single idea wrapped in padding. Write the shape next to it in the spreadsheet. Naming the shape tells you where to cut, and it stops you splitting sentences at random points that leave awkward fragments behind.
Step 4
Split at the idea boundaries
Break
chains with a full stop wherever a new idea starts, usually at and, but, so
or which. Move the main clause of a late-verb sentence to the front and give the condition
its own sentence. Turn hidden lists of three or more items into bullets or numbered steps. Give each
aside its own sentence or delete it if the reader does not need it. Keep each new sentence complete,
with its own subject and verb.
Step 5
Trim the padding that is left
Go
through the rewritten sentences and delete phrases that add length without meaning, such as it is important to note that,
in order to, due to the fact that, at this moment in time and
please be advised that. Replace them with to, because and now,
or remove them entirely. Many sentences drop below the flag after trimming alone and no longer need to
be split at all.
Step 6
Read the new version for rhythm and sense
Read the rewritten paragraphs aloud, or play them through text-to-speech. Check that every condition, exception and deadline from the original survived. Listen for runs of very short sentences that sound abrupt, and join two back together with a linking word where the ideas belong together. Then run the page through the checker again and confirm the average sentence length has fallen and the longest sentences are gone.
Keeping variety: the mistake after the fix
Once people learn that long sentences are flagged, a common overcorrection is to write everything in six-to-ten-word sentences. The average falls. The page gets harder to read in a different way.
Overcorrected: "Our boilers are efficient. They save you money. They are easy to install. We fit them in a day. We clean up afterwards. You get a ten-year guarantee."
Every sentence is short, but the text sounds like a list read aloud, and the reader has to work out how the ideas relate. Is the one-day fitting because installation is easy? Is the guarantee connected to the fitting?
Better: "Our boilers are efficient, so they cost less to run. Because they are simple to install, we can usually fit one in a day and clean up before we leave. Every installation comes with a ten-year guarantee."
The sentences now range from 7 to 20 words. The links between ideas are stated. The longest sits right at the checker's limit, and even if a later edit pushed it over, it would be fine to leave it.
Linking words that restore the connections, such as "so", "because" and "as a result", are covered in fixing weak or missing transitions.
Long sentences you can leave alone
- Straight-line sentences. If the subject and verb come early and the rest adds detail in order, a sentence of 25 or 30 words can read easily. Leave a few of these if the rest of the page is varied.
- Legal and regulated wording. Terms, financial disclosures and product safety statements may have to stay as approved. Put a plain summary above them rather than rewriting them. This is not legal advice; check any change with whoever approves the wording.
- Quotations. Do not rewrite a customer review or a quote from someone else to shorten it. Trim with an ellipsis if you must, or choose a shorter quote.
- Addresses and product names. A sentence that contains a full postal address or a long product name will be flagged for words the reader skims over. Move the address to its own line if you can.
- Deliberate style. A long, flowing sentence can be the right choice in storytelling or a brand's founding story. One or two on a page are a choice; a page full of them is a problem.
Where long sentences hide on common sites
Long sentences cluster in predictable places. Checking these first finds most of them quickly.
- Opening paragraphs. Writers often try to fit the whole page into the first sentence. Split it into the main point and the supporting detail.
- Delivery, returns and cancellation text. These pages are full of conditions and exceptions, which produce late-verb sentences. Lists and short "if this, then that" sentences work well here.
- Meta descriptions and product summaries. Squeezing many selling points into a short space produces long chains. Choose the two points that matter most.
- Text written by suppliers or agencies. It often arrives in a denser house style. Review it before publishing.
- Content from AI writing tools. Generated drafts often contain long sentences joined with "while", "which" and "ensuring". Edit them like any other draft.
On WordPress, readability plugins such as Yoast SEO also warn about sentence length in the editor, using their own thresholds. On Shopify and most hosted platforms there is no built-in check, so paste the text into a checker before publishing.
Stopping long sentences at the drafting stage
- Write one idea per sentence in the first draft. Joining sentences later is easier than untangling long ones.
- Put the subject and verb early. If a sentence starts with "For", "In the event that" or "With regard to", check whether the main clause could come first.
- Use a list whenever you write "and" for the third time. Three or more items, steps or requirements in one sentence almost always read better as a list.
- Add sentence length to your style guide. Say that you aim for an average in the mid-teens with plenty of variety, and that sentences over the checker's 20-word flag need a reason.
- Check before publishing. A quick pass through the checker catches the long sentences while they are still easy to fix.
Long sentences often sit inside long paragraphs; fixing paragraphs over four sentences covers that. For how sentence length feeds the overall score, see fixing a low Flesch Reading Ease score.
1. Why does the Readability Checker flag sentences over 20 words?
Because long sentences are one of the most common causes of hard-to-read web pages, and 20 words is a practical point at which to take a second look. Plain English guidance commonly suggests an average of around 15 to 20 words per sentence. The flag does not mean the sentence is wrong. It means it is worth checking whether it carries more than one idea, hides its main verb or packs a list into a single line of text.
2. Is it wrong to have any sentences longer than 20 words?
No. A sentence that moves in a straight line, with the subject and verb early and details following in order, can be easy to read at 25 or 30 words. Good writing varies sentence length, so some longer sentences are normal. The problem is a page where most sentences are long, or where long sentences carry several ideas, conditions or lists. Fix those, and leave well-built longer sentences where they help the rhythm.
3. What is the easiest way to shorten a long sentence?
Look for the word where a new idea starts, usually and, but, so or which, and put a full stop there. Then check that both halves are complete sentences with their own subject and verb. If the sentence contains three or more items, turn them into a bulleted list. Finally, delete padding such as in order to or it is important to note that. Those three moves fix most long sentences in web copy.
4. Will splitting sentences make my writing sound choppy?
It can if you split everything into very short sentences. A page made entirely of six-word sentences sounds abrupt, and readers have to work out how the ideas connect. Aim for a mix instead: mostly short and medium sentences, with the occasional longer one where it reads naturally. When two short sentences belong together, join them with a linking word such as because, so or but. Reading the page aloud is the quickest way to hear whether the balance is right.
5. Why does my tool say a bullet list is one long sentence?
Most readability tools decide where sentences end by looking for full stops, question marks and exclamation marks. A bullet list without any of those, together with its lead-in line, can be counted as one very long sentence. The fix is not to rewrite the list. Either ignore that flag, add a full stop to the end of each item, or make the lead-in a complete sentence ending in a colon, depending on how your tool counts.
6. How do I shorten sentences in legal or technical text?
Start with the parts you are allowed to change. Move conditions into their own sentences, turn lists of requirements into bullets and put the main instruction first. Where wording has been approved and cannot change, such as regulated disclosures or contract terms, add a short plain-language summary above it instead. For technical text, keep the precise terms your readers need and shorten the grammar around them. This is not legal advice, so check changes to legal wording with whoever approves it.
7. What average sentence length should I aim for?
Plain English guidance commonly points to an average of around 15 to 20 words, and many clear web pages sit in the mid-teens. The average matters less than the spread: a page averaging 16 words but containing several 45-word sentences will still lose readers at those points. Track the average in the Readability Checker over time, and pay most attention to the longest flagged sentences. Write the range you settle on into your style guide.
The Readability Checker reports average sentence length and flags the sentences that need attention, alongside Flesch Reading Ease, Flesch-Kincaid Grade Level, Gunning Fog, passive voice share, paragraph length and jargon density.
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