illvsIMOTell them apart

Quick tell: ill is a adverb, IMO is an abbrev, so they fill different roles in a sentence.

Which to use

“ill” is an adverb and “IMO” is an abbrev - they look or sound alike but fill different roles in a sentence.

#25,175
“ill” frequency rank
#21,299
“IMO” frequency rank
46474
confusion score

Side-by-Side Comparison

Feature ill IMO
Definition schlecht, falsch Institut für Marktökologie (Sitz in der Schweiz)

Where the eye mixes ill and IMO

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

3 ch
ill
3 ch
IMO

Look-alike desk: ill vs IMO

These two trip readers on the page rather than in the ear: ill is [ɪl] while IMO is [ˌiːɛmˈʔoː]. 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 (adverb vs abbrev), which is usually the fastest check. Our composite confusion score for this pair is 46474, derived from the frequency rank of both members and their visual similarity.

ill is recorded at frequency rank #25,175, classified as anadv, pronounced [ɪl]. IMO is at rank #21,299, tagged as anabbrev, pronounced [ˌiːɛmˈʔoː].

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 46474, this pair ranks #1,317,856 of 2,006,359 scored German confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of ill vs IMO

Shared letters: i. Private to "ill": l. Private to "IMO": mo.

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

Frequently Asked Questions

Is swapping "ill" for "IMO" ever safe?
No - they are not even the same part of speech. "ill" is an adverb and "IMO" an abbrev, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "ill" vs "IMO" - which ranks higher?
"IMO" is the more common of the two: it sits at frequency rank #21,299 in our German list, against #25,175 for "ill". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

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

  • Full dictionary entry for "ill" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "IMO" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #1,317,856 of 2,006,359 scored German confusable pairs in this corpus vintage. Corpus statistics
  • "ill" and "IMO" also get mixed up with nearby pairs, the highest-scored neighbour is "ill vs IMs". Nearby pair

Confusion rank #1,317,856 of 2,006,359 scored German pairs, corpus vintage 2026-09-03, not spelling advice.

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

Source: FrequencyWords open word-frequency list