ill vs IT, What's the Difference?

Which to use

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

#25,175
“ill” frequency rank: #1,011
“IT” frequency rank: 26186
confusion score

Side-by-Side Comparison

Feature	ill	IT
Definition	schlecht, falsch	Impulstelegrafie

Where the eye mixes ill and IT

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

3 ch

ill

2 ch

Why the eye confuses ill with IT

These two trip readers on the page rather than in the ear: ill is [ɪl] while IT is [aɪ̯ˈtiː]. 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 (adverb vs abbrev), which is usually the fastest check. Our composite confusion score for this pair is 26186, 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]. IT is at rank #1,011, tagged as anabbrev, pronounced [aɪ̯ˈtiː].

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 26186, this pair ranks #1,821,872 of 2,006,359 scored German confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of ill vs IT

Shared letters: i. Private to "ill": l. Private to "IT": t.

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

Frequently Asked Questions

Can "ill" and "IT" be used interchangeably?

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

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

"IT" is the more common of the two: it sits at frequency rank #1,011 in our German list, against #25,175 for "ill". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

After this comparison

Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.

Full dictionary entry for "ill" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "IT" - compare definitions side by side with the headword page. Word entry
This pair ranks #1,821,872 of 2,006,359 scored German confusable pairs in this corpus vintage. Corpus statistics
"ill" and "IT" also get mixed up with nearby pairs, the highest-scored neighbour is "ill vs IMs". Nearby pair

Confusion rank #1,821,872 of 2,006,359 scored German pairs, corpus vintage 2026-09-03, not spelling advice.