idavsillWhich spelling fits?

Quick tell: ida is a noun, ill is an adjective, so they fill different roles in a sentence.

Which to use

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

#5,206
“ida” frequency rank
#44,899
“ill” frequency rank
50105
confusion score

Side-by-Side Comparison

Feature ida ill
Definition ação, ato ou movimento de ir doente

Where the eye mixes ida and ill

Muted = shared; highlighted = the visual trap. They share 1 letter in sequence. ida (VCV) and ill (VCC) run the same length but a different consonant-vowel pattern - the shape difference is usually the fastest tell.

3 ch
ida
3 ch
ill

Look-alike desk: ida vs ill

These two trip readers on the page rather than in the ear: ida is /ˈi.dɐ/ while ill is /ɪl/. 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 (noun vs adjective), which is usually the fastest check. Our composite confusion score for this pair is 50105, derived from the frequency rank of both members and their visual similarity.

ida is recorded at frequency rank #5,206, classified as anoun, pronounced /ˈi.dɐ/. ill is at rank #44,899, tagged as anadj, pronounced /ɪl/.

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 50105, this pair ranks #14,871 of 75,631 scored Portuguese confusable pairs - among the most confusable pairs.

Orthographic DNA of ida vs ill

Shared letters: i. Private to "ida": ad. Private to "ill": l.

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

Frequently Asked Questions

Can "ida" and "ill" be used interchangeably?
No - they are not even the same part of speech. "ida" is a noun and "ill" an adjective, so a sentence built for one is usually ungrammatical with the other.
In ordinary Portuguese text, does "ida" or "ill" show up more?
"ida" is the more common of the two: it sits at frequency rank #5,206 in our Portuguese list, against #44,899 for "ill". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

Eye-level mix-up between "ida" and "ill" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "ida" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "ill" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #14,871 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
  • "ida" and "ill" also get mixed up with nearby pairs, the highest-scored neighbour is "ill vs ino". Nearby pair

Confusion rank #14,871 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.

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

Source: FrequencyWords open word-frequency list