Qu et C: orthographe et son

If you have ever said kwee for qui or kwa for quoi, this page is for you. The French qu digraph almost never represents the /kw/ sound that English speakers expect from words like queen, quick, or quite. In the overwhelming majority of French words, qu is just /k/ — a single consonant, with the u purely orthographic and silent.

This page lays out the complete French system for writing the /k/ sound and how it interacts with the soft /s/ that c can also represent. By the end you should be able to read every common /k/-word and predict the spelling of any new one.

The fundamental rule: qu = /k/

In nearly every French word, qu is a single consonant /k/. The u is silent and is there only to make the spelling work — it tells the reader "this is a /k/ before a front vowel."

The single most useful word to drill is qui. English speakers reach for /kwi/ on instinct. The correct French is /ki/, just two sounds: /k/ + /i/. Spend a minute saying qui qui qui with no /w/ at all and you have neutralized the most common pronunciation transfer error.

The historical reason

In Latin, the spelling qu genuinely represented /kw/ — qui in classical Latin was /kwiː/, quattuor (four) was /ˈkwattʊɔr/. As Vulgar Latin evolved into French, the /w/ glide weakened and disappeared in most contexts. By Old French, qui was already /ki/ and quatre was /katrə/. The spelling qu survived because medieval scribes preserved Latin orthography even after the pronunciation had moved on.

Spanish and Italian show the same pattern: Spanish qué /ke/, Italian che /ke/ (which dropped the u entirely), both descended from the same Latin /kw/. English, in contrast, preserved the original /kw/ in most positions (queen, quick, quite), borrowing the spelling from Latin/French but keeping a different sound. This is exactly the trap that catches English speakers reading French.

Why qu instead of just c?

You may wonder why French bothers with qu at all, given that c before e/i/y could in theory represent /k/ in some other writing system. The answer is the c/g soft-hard rule (covered in detail at pronunciation/c-and-g-soft-vs-hard): in French, c before e, i, or y is automatically soft /s/. So if you wanted to write the word qui with a c, the spelling ci would be read /si/ ("here" in old usage). To represent /k/ + front vowel, French needs an alternative spelling — and that spelling is qu.

This explains the distribution:

• /k/ + back vowel (a, o, u): use c — café, cou, cure.
• /k/ + front vowel (e, i, y): use qu — queue, qui, no common /k/ + y example because y is rare.
• /k/ at end of word, sometimes with no vowel: use c or que — bec /bɛk/ ends in c; chaque /ʃak/ ends in que. (Word-final que is the standard way to write /k/ at the end of a word: boutique, fantastique, politique, publique.)

The handful of /kw/ exceptions

There are a small number of French words where qu really does represent /kw/ — almost all of them are scientific, technical, or learned borrowings from Latin where the original /kw/ was preserved.

These are the exceptions you must memorize. Note that quoi is sometimes counted in this list, but the /w/ in quoi /kwa/ comes from the digraph oi, not from qu. Quoi is qu /k/ + oi /wa/ = /kwa/, which happens to sound like English qu + a vowel.

C as /k/ vs c as /s/: a recap

The full /k/-and-/s/ system depends on how French distributes the two sounds across letters. The table is worth memorizing as a single unit:

The two systems run in parallel and complementary ways. The letter c alone is ambiguous — it could be /k/ or /s/, depending on the next vowel. The cedilla disambiguates one direction (ç is always /s/) and the digraph qu disambiguates the other direction (qu is almost always /k/).

K: borrowed letters

The letter k is rare in French. It appears almost exclusively in borrowings:

Note that kiosque uses k at the start (because the word was borrowed) and the standard French -que at the end (because -que is the native /k/-final spelling). French rarely creates new words with k; even modern borrowings often get rewritten with c or qu over time.

Word-final /k/: cinq, lac, sec, donc

When /k/ appears at the end of a French word, the most common spellings are -c and -que. A few short, high-frequency words end in plain -c:

Cinq is the only common French word ending in -q alone, and the q really is pronounced. (Coq /kɔk/, cinq /sɛ̃k/.)

Comparing the systems: ç vs qu

Here is the conceptual symmetry, made explicit. French has two "override" devices for the c letter:

The cedilla and the qu digraph are mirror solutions to mirror problems. Together they let French write any /k/ and any /s/ in any position, while keeping c available as a flexible letter that defaults to context-appropriate behavior.

Drill: read these aloud

Common Mistakes

Key takeaways

In French, qu almost always represents the single consonant /k/. The u is silent and exists only because c before e/i/y would be soft /s/, requiring an alternative spelling for /k/. The handful of /kw/-pronounced qu words (aquarium, équation, quartz) are scientific borrowings and must be memorized — but they are dwarfed by the thousands of words where qu is just /k/. Pair this with the c/g soft-hard system (ç for /s/ before back vowels, qu for /k/ before front vowels) and you have a complete model of how French writes its /k/ and /s/ sounds.