C4vsCDUWhich spelling fits?

Which to use

“C4” and “CDU” are a confusable German pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#30,979
“C4” frequency rank
#614
“CDU” frequency rank
31593
confusion score

Side-by-Side Comparison

Feature C4 CDU
Definition Abkürzung für die Pfadüberdeckung Christlich Demokratische Union [Deutschlands]

Where the eye mixes C4 and CDU

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

2 ch
C4
3 ch
CDU

Visual trap between C4 and CDU

A purely visual mix-up. C4 ([t͡seːˈfiːɐ̯]) and CDU ([tseːdeːˈʔuː]) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they differ by 1 letter(s) in length. Our composite confusion score for this pair is 31593, derived from the frequency rank of both members and their visual similarity.

C4 is recorded at frequency rank #30,979, classified as anabbrev, pronounced [t͡seːˈfiːɐ̯]. CDU is at rank #614, tagged as anabbrev, pronounced [tseːdeːˈʔuː].

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 31593, this pair ranks #1,724,992 of 2,006,359 scored German confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of C4 vs CDU

Shared letters: c. Private to "C4": -. Private to "CDU": du.

"C4" · 1 letters · shape C  ·  "CDU" · 3 letters · shape CCV

Frequently Asked Questions

Can "C4" and "CDU" be used interchangeably?
No. They are said differently ([t͡seːˈfiːɐ̯] versus [tseːdeːˈʔuː]) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
In ordinary German text, does "C4" or "CDU" show up more?
"CDU" is the more common of the two: it sits at frequency rank #614 in our German list, against #30,979 for "C4". 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 "C4" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "CDU" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #1,724,992 of 2,006,359 scored German confusable pairs in this corpus vintage. Corpus statistics
  • "C4" and "CDU" also get mixed up with nearby pairs, the highest-scored neighbour is "C4 vs CCS". Nearby pair

Confusion rank #1,724,992 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