IIvsIVConfusable pair

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

Which to use

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

#1,020
“II” frequency rank
#3,762
“IV” frequency rank
4782
confusion score

Side-by-Side Comparison

Feature II IV
Definition Initialism of illegal immigrant. Abbreviation of intravenous.

Letter map: II vs IV

Shared letters muted; letters that set II and IV apart highlighted. Shared run: 1.

2 ch
II
2 ch
IV

Role in the sentence - II and IV

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: II is anoun and IVanadjective. On the page they differ by a single letter - i in “II” becomes v in “IV”. Our composite confusion score for this pair is 4782, derived from the frequency rank of both members and their visual similarity.

II is recorded at frequency rank #1,020, classified as anoun. IV is at rank #3,762, tagged as anadj, pronounced /ˌaɪ ˈviː/.

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 4782, this pair ranks #517,701 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of II vs IV

Shared letters: i. Private to "II": -. Private to "IV": v.

"II" · 2 letters · shape VV  ·  "IV" · 2 letters · shape VC

Frequently Asked Questions

Can "II" and "IV" be used interchangeably?
No - they are not even the same part of speech. "II" is a noun and "IV" an adjective, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "II" or "IV"?
"II" is the more common of the two: it sits at frequency rank #1,020 in our English list, against #3,762 for "IV". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

You've compared "II" and "IV". Here's where to go from here.

  • Full dictionary entry for "II" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "IV" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #517,701 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "II" and "IV" also get mixed up with nearby pairs, the highest-scored neighbour is "ith vs IV". Nearby pair

Confusion rank #517,701 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.

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

Source: FrequencyWords open word-frequency list