illvsisiWhat's the difference?

Quick tell: ill is a adjective, isi is a verb, so they fill different roles in a sentence.

Which to use

“ill” is an adjective and “isi” is a verb - they look or sound alike but fill different roles in a sentence.

#15,649
“ill” frequency rank
#49,170
“isi” frequency rank
64819
confusion score

Side-by-Side Comparison

Feature ill isi
Definition Malade, malsain. Deuxième personne du singulier du futur de l’indicatif du verbe isal/isañ.

Where the eye mixes ill and isi

Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.

3 ch
ill
3 ch
isi

Spelling & Dictionary Insight

These two trip readers on the page rather than in the ear: ill is \ˈɪl\ while isi is \ˈisːi\. Spoken aloud the problem disappears. In writing it persists, because they share most of their letters but differ in 2 positions, and the parts of speech differ too (adjective vs verb), which is usually the fastest check. Our composite confusion score for this pair is 64819, derived from the frequency rank of both members and their visual similarity.

ill is recorded at frequency rank #15,649, classified as anadj, pronounced \ˈɪl\. isi is at rank #49,170, tagged as averb, pronounced \ˈisːi\.

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 64819, this pair ranks #75,181 of 440,172 scored French confusable pairs - among the most confusable pairs.

Orthographic DNA of ill vs isi

Shared letters: i. Private to "ill": l. Private to "isi": s.

"ill" · 3 letters · shape VCC  ·  "isi" · 3 letters · shape VCV

Frequently Asked Questions

Can "ill" and "isi" be used interchangeably?
No - they are not even the same part of speech. "ill" is an adjective and "isi" a verb, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "ill" or "isi"?
"ill" is the more common of the two: it sits at frequency rank #15,649 in our French list, against #49,170 for "isi". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

You've compared "ill" and "isi". Here's where to go from here.

  • Full dictionary entry for "ill" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "isi" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #75,181 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • "ill" and "isi" also get mixed up with nearby pairs, the highest-scored neighbour is "ime vs isi". Nearby pair

PlainSpell is a reference corpus, not spelling advice. Verify unusual forms in context.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list