houillevshouillerWhich spelling fits?

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

Which to use

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

#30,205
“houille” frequency rank
#41,827
“houiller” frequency rank
72032
confusion score

Side-by-Side Comparison

Feature houille houiller
Definition Charbons fossiles appelés communément charbons de terre. Qui se rapporte à la houille.

Where the eye mixes houille and houiller

Muted = shared; highlighted = the visual trap. They share 7 letters in sequence. houille runs 7 letters (CVVVCCV) against houiller's 8 (CVVVCCVC) - the length gap alone is often enough to separate them once you know to check it.

7 ch
houille
8 ch
houiller

Why the eye confuses houille with houiller

These two trip readers on the page rather than in the ear: houille is ^((h aspiré))\uj\ while houiller is ^((h aspiré))\u.je\. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 extra letter(s) - “houille” sits inside “houiller”, and the parts of speech differ too (noun vs adjective), which is usually the fastest check. Our composite confusion score for this pair is 72032, derived from the frequency rank of both members and their visual similarity.

houille is recorded at frequency rank #30,205, classified as anoun, pronounced ^((h aspiré))\uj\. houiller is at rank #41,827, tagged as anadj, pronounced ^((h aspiré))\u.je\.

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 72032, this pair ranks #45,450 of 440,172 scored French confusable pairs - among the most confusable pairs.

Orthographic DNA of houille vs houiller

Shared letters: ehilou. Private to "houille": -. Private to "houiller": r.

"houille" · 7 letters · shape CVVVCCV  ·  "houiller" · 8 letters · shape CVVVCCVC

Known mistypes of this pair

  • houillehhouille · hoiulle · houile · houilel · houlile · huoille · ohuille
  • houillerhhouiller · hoiuller · houilelr · houiler · houillerr · houillre · houliler · huoiller

Frequently Asked Questions

Can "houille" and "houiller" be used interchangeably?
No - they are not even the same part of speech. "houille" is a noun and "houiller" an adjective, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "houille" or "houiller"?
"houille" is the more common of the two: it sits at frequency rank #30,205 in our French list, against #41,827 for "houiller". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

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

  • Full dictionary entry for "houille" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "houiller" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #45,450 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • "houille" and "houiller" also get mixed up with nearby pairs, the highest-scored neighbour is "houiller vs houillères". 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 #45,450 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