Which to use
“ill” is an adjective and “isla” is a noun - they look or sound alike but fill different roles in a sentence.
- #43,059
- “ill” frequency rank
- #939
- “isla” frequency rank
- 43998
- confusion score
Side-by-Side Comparison
| Feature | ill | isla |
|---|---|---|
| Definition | Enfermo. | Territorio rodeado completamente por agua. |
Where the eye mixes ill and isla
Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.
Visual trap between ill and isla
These two trip readers on the page rather than in the ear: ill is /ɪl/ while isla is [ˈisla]. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 letter(s) in length, and the parts of speech differ too (adjective vs noun), which is usually the fastest check. Our composite confusion score for this pair is 43998, derived from the frequency rank of both members and their visual similarity.
ill is recorded at frequency rank #43,059, classified as anadj, pronounced /ɪl/. isla is at rank #939, tagged as anoun, pronounced [ˈisla].
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 43998, this pair ranks #139,486 of 323,831 scored Spanish confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of ill vs isla
Shared letters: il. Private to "ill": -. Private to "isla": as.
"ill" · 3 letters · shape VCC · "isla" · 4 letters · shape VCCV
Known mistypes of this pair
- isla ← ilsa · isal · islla · issla
Frequently Asked Questions
Is swapping "ill" for "isla" ever safe?
Which is more common, "ill" or "isla"?
What to do next
Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.
- Full dictionary entry for "ill" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "isla" - compare definitions side by side with the headword page. Word entry
- This pair ranks #139,486 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
- "ill" and "isla" also get mixed up with nearby pairs, the highest-scored neighbour is "ill vs iza". 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 #139,486 of 323,831 scored Spanish pairs, corpus vintage 2026-09-03, not spelling advice.