ill vs IR, What's the Difference?

Which to use

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

#25,175
“ill” frequency rank: #14,329
“IR” frequency rank: 39504
confusion score

Side-by-Side Comparison

Feature	ill	IR
Definition	schlecht, falsch	infrarot, Infrarot

Letter map: ill vs IR

Shared letters muted; letters that set ill and IR apart highlighted. Shared run: 1.

3 ch

ill

2 ch

Grammar separator: ill vs IR

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: ill is anadverb and IRanabbrev. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 39504, 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]. IR is at rank #14,329, tagged as anabbrev.

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 39504, this pair ranks #1,534,952 of 2,006,359 scored German confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of ill vs IR

Shared letters: i. Private to "ill": l. Private to "IR": r.

"ill" · 3 letters · shape VCC · "IR" · 2 letters · shape VC

Frequently Asked Questions

Is swapping "ill" for "IR" ever safe?

No - they are not even the same part of speech. "ill" is an adverb and "IR" an abbrev, so a sentence built for one is usually ungrammatical with the other.

Which is more common, "ill" or "IR"?

"IR" is the more common of the two: it sits at frequency rank #14,329 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

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

Full dictionary entry for "ill" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "IR" - compare definitions side by side with the headword page. Word entry
This pair ranks #1,534,952 of 2,006,359 scored German confusable pairs in this corpus vintage. Corpus statistics
"ill" and "IR" also get mixed up with nearby pairs, the highest-scored neighbour is "ill vs IMs". Nearby pair

Confusion rank #1,534,952 of 2,006,359 scored German pairs, corpus vintage 2026-09-03, not spelling advice.