Is eaux countable or not? The question arises given that it is the plural form of eau.

If it is countable, it can mean bodies of water. However, if it is uncountable, then how is it the plural form of eau?

And which characteristic (countable/uncountable) applies to eaux when it is used to refer to different types of water (like H₂O or D₂O)?

  • 2
    I can't see how your question is specific to French, you could ask the same question about water/waters in English (see Water, a water and waters). Maybe you could try to consider that eaux is not the lexical plural of eau and that eau when singular (unaccountable) is a substance, and when plural (countable) an area (made of water). You could have a look at this as well.
    – None
    Jun 18, 2023 at 11:27
  • 4
    Words themselves can't always be classified as countable or uncountable; it's their specific meanings that are countable or uncountable. So to answer your question, we need a specific sentence containing eaux. For example, in English, in she has red hair, the word hair is uncountable, but in there is a hair in my soup, it is countable. Something similar happens in French — cheveux (hair) is nearly always used in the plural. I don't know whether this usual use of cheveux is officially classified as uncountable in french; I don't believe it makes any difference to the grammar. Jun 18, 2023 at 12:53
  • Refer to noms indénombrables that don't support plural, unless there is a specific situation where the noun is countable.
    – Graffito
    Jun 19, 2023 at 16:00

2 Answers 2


When you mean "chemical compound", then "eau" is uncountable, speaking generally; in French you say "indénombrable", (also) "non dénombrable", and also "non comptable" (Kalmbach).

It is more precisely a "nom indénombrable massique".

It becomes "comptable" by "découpe en unités" (nombre et noms massifs). For instance, mineral water as drawn from one spring is different from that in another spring; as such it becomes a unit and you can speak about "une eau minérale" and "les eaux minérales des Alpes" for instance; you have in fact the possibility to count the "eaux minérales" drawn from springs in the Alps.

When you speak about a body of water, as in "eaux territoriales", you still call "eaux" "indénombrable" or "non comptable" in French, but it should not be translated by "uncountable" in English. In English, "uncountable" is the French "massique" (Oxford Advanced Learner's Dictionary); see also "A Comprehensive Grammar of the English Language": "Non count nouns are singular and invariable". This type of noun ("indénombrable", in French) is more particularly called a plurale tantum (Wikipédia). The same term is used in English (pluralia tantum in s (thanks, looks, pains, etc.)).

This usage of "eaux" uniquely in the plural is found in connection with the drinking of the water of a particular spring because it is believed its water has some special qualities (healing, good for your health). This is largely a usage of the past but modern authors might still revert to it (boire les eaux).

(L'eau et le feu: la courte mais trépidante aventure de la ... - Bertrand Dardenne · 2005) couleur rouille : on boit alors l'eau dépurée . En prolongeant le temps d'exposition , l'eau devient inactive et perd ses qualités thermales . Le public et les curistes viennent boire les eaux , ferrugineuses et laxatives , " pour

There are cases where nothing can be said about the number of "eaux"; this is the case for the idiom "entre deux eaux"; this is so because you can't analyse this expression, it has a set meaning.
(Expressio : en manoeuvant entre deux partis sans se compromettre ; en refusant de s'engager ; sur une ligne de crète ; en évitant de se compromettre)


Pour ce qui est de eau au singulier, on dit couramment commander une eau (minérale, gazeuse..), et même apparemment de plus en plus fréquemment:

enter image description here

Je voudrais aussi signaler qu'on trouve de temps en temps l'expression eau territoriale au singulier:

enter image description here


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.