Which to use
“fastened” is a verb and “flattened” is an adjective - they look or sound alike but fill different roles in a sentence.
- #28,204
- “fastened” frequency rank
- #18,080
- “flattened” frequency rank
- 46284
- confusion score
Side-by-Side Comparison
| Feature | fastened | flattened |
|---|---|---|
| Definition | simple past and past participle of fasten | Made flat by something. |
Letter map: fastened vs flattened
Shared letters muted; letters that set fastened and flattened apart highlighted. Shared run: 7. fastened runs 8 letters (CVCCVCVC) against flattened's 9 (CCVCCVCVC) - the length gap alone is often enough to separate them once you know to check it.
Role in the sentence - fastened and flattened
Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: fastened is averb and flattenedanadjective. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 46284, derived from the frequency rank of both members and their visual similarity.
fastened is recorded at frequency rank #28,204, classified as averb, pronounced /ˈfɑːsn̩d/. flattened is at rank #18,080, tagged as anadj.
Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.
With a confusion score of 46284, this pair ranks #213,225 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of fastened vs flattened
Shared letters: adefnt. Private to "fastened": s. Private to "flattened": l.
"fastened" · 8 letters · shape CVCCVCVC · "flattened" · 9 letters · shape CCVCCVCVC
Known mistypes of this pair
Frequently Asked Questions
Can "fastened" and "flattened" be used interchangeably?
Frequency check: "fastened" vs "flattened" - which ranks higher?
Useful next steps
You've compared "fastened" and "flattened". Here's where to go from here.
- Full dictionary entry for "fastened" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "flattened" - compare definitions side by side with the headword page. Word entry
- This pair ranks #213,225 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "fastened" and "flattened" also get mixed up with nearby pairs, the highest-scored neighbour is "fastened vs fastener". Nearby pair
- Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes
Confusion rank #213,225 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.