I am really confused as to when I am supposed to use just "de" and when I am supposed to use de with le or la to form "du" and "de la". Right now I can't figure out if there is a rule or if it is just a matter of personal preference.

I have a picture dictionary that I use for my vocabulary training and some terms use just de and others use du or de la. For example (and this is just one of many instances I've come across in my dictionary) The Great Barrier Reef is called (at least in my picture dictionary) "La Grande Barrière de Corail" (notice that in this one only "de" is used), while The Tropic of Capricorn is called "Le tropique du Capricorne" (notice that here "du" is used). Why couldn't both have used "de" or for that matter "du"? Is there a rule here that I am missing or is this just arbitrary and simply a matter of preference meaning that both could be used depending on what we like better?

In particular I am not asking for different usages of partitive article. Specifically I am interested in why certain terms use de and why others use de + le (to form du) or de la. I am familiar with the uses of partitive article de and the rules of when it should be used, but my dictionary contains terms which are composed of multiple words where those rules don't necessarily apply (or at least I can't seem to fit those terms into rules for the use of de, de la or du) as in the examples I laid out above. I would like to know if there is a rule for terms like that when de, du or de la should be used. Another example would be le siège du chauffeuf (driver's seat) and le levier de vitesses (gear lever). The rules for partitive articles don't seem to have anything to do with these terms (at least I can't see the relationship, but if there is one I'd really appreciate the explanation). L'affichage du volume (gas meter display - on a gas pump) is another example where I don't understand why it couldn't also be l'affichage de volume. I am looking for a rule (if there is one) as to how these terms are formed using de or du/de la.

  • "Why couldn't both have used "de" or for that matter "du"?" - to make sure you live by your motto ;-)
    – Frank
    Commented Jan 14, 2017 at 15:01
  • Despite this being marked as already answered in another question I still can't find the answer to my question why some terms from my picture dictionary use de and others use du and de la. If someone can please point me to the specific part of the answer in the other question which answers my question I would really appreciate it. Commented Jan 18, 2017 at 23:10

2 Answers 2


In the first case, when you say "la barrière de Corail", de stands for a particle indicating the substance that makes up the thing you're talking about. It means that the reef is composed of coral, you could implicitly say "la barrière (faite de) corail". Normally when talking about the matter an object is made of, people use en (e.g. un gilet en laine: a wool jacket ; un mur en béton: a concrete wall). But here if you say "la barrière en corail" it'll sound like coral has been crushed and turned into bricks in order to make a wall. "La barrière de corail" rather sounds like coral has been growing all around and has spontaneously formed a reef. It also sounds more elegant. ("La barrière du corail" would sound like you're talking about a specific coral as a topic).

About the "Tropique du Capricorne", the le from du (= de le, just to be clear) simply comes from the fact that capricorn is an astrological sign, which are usually referred to using an article: La constellation du Capricorne; Être né sous le Capricorne. "Tropique de Capricorne" would sound like Capricorne is a person, like a great explorer etc... (just like in "Détroit de Magellan"). That's it, hope it helps!

  • This seems strangely specific to the precise examples given. What about la rame de train, la maison de poupée, le devoir de géographie, ... ? While capricorne is used with a definite in the examples, it seems not to be a property of the noun, la tête de capricorne en haut à droite is ok as well as l'imitation de corail.
    – GAM PUB
    Commented Jan 14, 2017 at 18:34
  • In some of the expressions you cite, the relation between both nouns is not the same as the one we're talking about, i.e. de has not the same function. Le gilet de laine, le pot de terre or here la barrière de corail all define a relation so that the first noun is physically composed of the second one. In la maison de poupée, de rather define a relation of belonging between both nouns (the house "belongs" to the doll). Le devoir de géographie doesn't show a relation of object/substance either.
    – Chewie
    Commented Jan 14, 2017 at 21:39
  • La rame de train however means that the carriage is made of trains in terms of discrete elements, which is in fact comparable to barrière de corail (if the elements were made of a substance, as in my examples terre and laine, you could replace de by en). As for the capricorne thing, this word is also a common noun and designates an animal, but the expression tropique du Capricorne, as shows the capital letter, it refers to the proper noun which usually comes with an article.
    – Chewie
    Commented Jan 14, 2017 at 21:39
  • Chewie, I think I understand your answer to the examples I have given, but in my dictionary there are others which I am struggling to fit into the explanations you gave. For example: La lumière du jour for daylight (is it because light belongs to the day so it's more specific and thus uses "du"?). Another example is: La porte de la véranda for balcony door, but la cabine de douche for shower cabin. I still can't see the difference here. The cabin belongs to the shower as much as the door belongs to the balcony, at least in my view, but one uses "de" and the other uses "de la". Commented Jan 15, 2017 at 10:32
  • I think your last examples are actually different. A veranda is kind of a room made of glass, and the door belongs to this room as it is a part of its walls. On the other hand, a douche is not an object (the dictionnary says it designates the water you shower with), but here you cannot say the water is a part of the cabine (which designates a small space made of 4 walls), the relation between them is rather that you shower in the cabine, i.e. the cabine is the place in which you perform the action, and thus you use it to shower.
    – Chewie
    Commented Jan 15, 2017 at 11:56

il y a plusieurs interprétations pour ces termes, et pour éviter la confusion on prend ces exemples :

  • Devoir de français.

  • Devoir du Français.

  • Devoir de la police française.

-Dans la première phrase on parle de la langue et donc d'une caractéristique.

-Dans la seconde on parle de la personne (masculine).

-Dans la dernière on parle de la personne (féminine).

Remarque : il y a un autre usage pour le (Du/De/De La), qui sont des articles partitifs, exemple, "Il mange du pain" !

  • L’appellation correcte est article, et mon exemple sur les partitifs est correcte et ce n'est pas le problème posé ici !
    – Bo Halim
    Commented Jan 14, 2017 at 18:45
  • 2
    L'exemple de partitif n'en est pas un... Vraiment ! => il a mangé du riz
    – GAM PUB
    Commented Jan 14, 2017 at 21:34
  • 1
    En fait l'article partitif, comme l'indique son nom, partage/compte un montant d'une certaine chose. Par contre quand on dit de pour indiquer une provenance, même si de se contracte de la même façon avec le pour former du, il ne compte pas de quantité, donc ce n'est pas un article partitif.
    – Chewie
    Commented Jan 14, 2017 at 21:57
  • @GAM PUB je n'ai pas exclu le partitif, j'ai dit que ce n'est pas le problème posé ici, d'où l'intérêt de ma Remarque, ma réponse sert à éviter la confusion rien de plus, rien de moins.
    – Bo Halim
    Commented Jan 14, 2017 at 22:14
  • @Chewie oui j'avoue m'être trompé en utilisant le terme "Pronoms" mais article englobe tout, ou comme a dit GAM PUB on peut utiliser déterminant !
    – Bo Halim
    Commented Jan 14, 2017 at 22:15

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