prolongevsprolongerWhich spelling fits?

Quick tell: prolonge is a noun, prolonger is a verb, so they fill different roles in a sentence.

Which to use

“prolonge” is a noun and “prolonger” is a verb - they look or sound alike but fill different roles in a sentence.

#11,108
“prolonge” frequency rank
#8,016
“prolonger” frequency rank
19124
confusion score

Side-by-Side Comparison

Feature prolonge prolonger
Definition Cordage qui servait, dans le tir, à réunir la pièce d’artillerie à son avant-train. Faire durer plus longtemps.

Where the eye mixes prolonge and prolonger

Muted = shared; highlighted = the visual trap. They share 8 letters in sequence.

8 ch
prolonge
9 ch
prolonger

Visual trap between prolonge and prolonger

These two trip readers on the page rather than in the ear: prolonge is \pʁɔ.lɔ̃ʒ\ while prolonger is \pʁɔ.lɔ̃.ʒe\. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 extra letter(s) - “prolonge” sits inside “prolonger”, and the parts of speech differ too (noun vs verb), which is usually the fastest check. Our composite confusion score for this pair is 19124, derived from the frequency rank of both members and their visual similarity.

prolonge is recorded at frequency rank #11,108, classified as anoun, pronounced \pʁɔ.lɔ̃ʒ\. prolonger is at rank #8,016, tagged as averb, pronounced \pʁɔ.lɔ̃.ʒe\.

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 19124, this pair ranks #374,872 of 440,172 scored French confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of prolonge vs prolonger

Shared letters: eglnopr. Private to "prolonge": -. Private to "prolonger": -.

"prolonge" · 8 letters · shape CCVCVCCV  ·  "prolonger" · 9 letters · shape CCVCVCCVC

Known mistypes of this pair

  • prolongeporlonge · pprolonge · prloonge · prollonge · prolnoge · prologne · proloneg · prolongge
  • prolongerporlonger · pprolonger · prloonger · prollonger · prolnoger · prologner · prolonegr · prolongerr

Frequently Asked Questions

Is swapping "prolonge" for "prolonger" ever safe?
No - they are not even the same part of speech. "prolonge" is a noun and "prolonger" a verb, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "prolonge" or "prolonger"?
"prolonger" is the more common of the two: it sits at frequency rank #8,016 in our French list, against #11,108 for "prolonge". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.

  • Full dictionary entry for "prolonge" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "prolonger" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #374,872 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • "prolonge" and "prolonger" also get mixed up with nearby pairs, the highest-scored neighbour is "prolonge vs prolongera". Nearby pair
  • Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes

Confusion rank #374,872 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.

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

Source: FrequencyWords open word-frequency list