IJ vs IV, What's the Difference?

Which to use

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

#46,535
“IJ” frequency rank: #3,762
“IV” frequency rank: 50297
confusion score

Side-by-Side Comparison

Feature	IJ	IV
Definition	A lake (formerly a bay) adjoining the city of Amsterdam, Netherlands.	Abbreviation of intravenous.

Where the spellings diverge

Shared letters are muted; the letters that actually set IJ and IV apart are highlighted. They share 1 letter in sequence, which is exactly why the eye skips the difference.

2 ch

Spelling & Dictionary Insight

These two trip readers on the page rather than in the ear: IJ is /eɪ/ while IV is /ˌaɪ ˈviː/. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - j in “IJ” becomes v in “IV”, and the parts of speech differ too (name vs adjective), which is usually the fastest check. Our composite confusion score for this pair is 50297, derived from the frequency rank of both members and their visual similarity.

IJ is recorded at frequency rank #46,535, classified as aname, pronounced /eɪ/. 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 50297, this pair ranks #175,581 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of IJ vs IV

Shared letters: i. Private to "IJ": j. Private to "IV": v.

"IJ" · 2 letters · shape VC · "IV" · 2 letters · shape VC

Frequency comparison

IJ#46,535

IV#3,762

Source: FrequencyWords open word-frequency list

Frequently Asked Questions

Can "IJ" and "IV" be used interchangeably?

No - they are not even the same part of speech. "IJ" is a name and "IV" an adjective, so a sentence built for one is usually ungrammatical with the other.

Which is more common, "IJ" or "IV"?

"IV" is the more common of the two: it sits at frequency rank #3,762 in our English list, against #46,535 for "IJ". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

Remembering IJ vs IV

The fastest way to pick the right one every time.

Check the role first: if you need a name, it's “IJ”; for an adjective, it's “IV”.
See each word in full, definition, IPA, etymology and its other confusables. Full “IJ” entry
Browse more pairs most likely to be confused. Most confusable