Why is teaching French partitives so hard?

While writing a couple of PowerPoints recently for frenchteacher, I was reminded about how tricky it is to teach, and for pupils to acquire, partitive articles in French (du, de la and des).

Firstly, here is a a pretty good description of how they work from the site frenchtoday.com;

"The French partitive articles express a notion of quantity: a vague one, a non-specific one.
These articles are often used after the verbs vouloir (Je voudrais du vin) or avoir (J’ai des chats) and with food. It’s the notion of “some” in English, but we don’t always use the word “some”. Often, we use nothing at all. In French, you need to “accompany” your word with something.

1. Je voudrais de l’eau, s’il vous plaît. (some water, maybe a glass, or maybe a bottle…)
2. Le professeur a de la patience. (patience ; you are not saying how much patience the teacher has, just that he/she has some)
3. Voici du gâteau. (some of it, not the whole cake)

To describe an unspecified plural quantity, use des (both feminine and masculine)
. This tells you there is more than one item, but again, it’s a vague plural quantity (could be 2, could be 10,000 or more)… This des usually applies to whole items, that you could count, but decided not to.

1. J’ai des Euros. (more than one, but I am not telling exactly how many).
2. Je vais acheter des pommes. (I’m going to buy apples. In English, we’d probably won’t use an article there. Maybe some, but not necessarily. In French, you need to use “des”).
3. Elle a des amies formidables (she has (some) great friends)."

Now, the main difficulty with getting students to use these accurately is the transfer effect (or interference effect, if you prefer) of English, when it's the L1. Even I, as a long term fairly fluent and very accurate speaker of French, occasionally hesitate between partitive and definite articles. The issue is, of course, that in English we often omit to use an article at all, so learners have to work out the underlying meaning of the utterance. One minor example of this is the fact that with feminine nouns French uses two words, not just one, e.g. il a de la patience. This at first view seems implausible to a native English speaker.

Further problems arise when students have to use negatives (when in English we use either any or nothing, e.g. "I don't have any apples" or "I don't have apples" - je n'ai pas de pommes) or specific quantities , e.g. "a bottle of milk" (une bouteille de lait). Not to mention the problem with nouns beginning with vowels or non-aspirate h's (J'ai de l'argent,  je n'ai pas d'argent or pas d'histoires!).

So compare:

I drank some wine with my dinner (easy - use the partitive du).
I drank wine with my dinner (pretty easy, because you know you could insert the word "some" if you wanted to).
I love wine (definite article le because there is an underlying notion of a general opinion about, in this case, "all wine").
I always drink wine with my dinner. (French natives report most often this would be du, but there is some doubt - subtlety of meaning may come into play).
Drink wine! (Bois le vin or Bois du vin?)

Now, given the difficulties involved for novice learners, how might we best help them get these right?

Well, firstly in the long run they will get a good feel for them after lots and lots of listening and reading input. This may be the only way they really acquire them properly.

In the shorter term, when you teach them more explicitly, here are my own suggestions which represent a sort of attack on all fronts.

1. Present them frequently in meaningful input ("flood the input", as they sometimes say). This exploits implicit (natural) learning processes or inductive learning (picking up the grammar rule through examples). This would be my number one priority.
2. Explain how they are translated into English (as in the above example from frenchtoday.com).
3. Teach them separately from other articles, introducing them later than indefinite and definite articles (e.g. in Y8 in England and wales) so as to avoid sowing confusion. This means carefully selecting what you will teach in your scheme of work, delaying teaching situations such as shopping or going to the cafe. (This reveals a potential problem with task-based syllabuses if you feel that selecting and grading of grammar is important.)
4. Take advantage of positive transfer from English by saying that for "any" use de and for "of" say de. This will help pupils get the point that a bottle OF milk is une bouteille de lait).
5. Teach and practise set chunks like Pas de problème, un litre de lait and J'ai de l'argent)
6. When creating vocabulary lists or knowledge organisers, show longer chunks rather than isolated words when appropriate. This lets students see the articles in meaningful contexts.
7. Practise them repeatedly using a range activities, e.g. transcription, translation, gap-fill. But don't create too much confusion in the early stages by asking for choices between different types of articles - only the very smartest pupils will cope with this.
8. When creating presentations separate out masculine, feminine and plural and highlight the words in writing ("enhancing the input").
9. When explaining the difference between du and de la, say that du is really like de le in disguise and compare it with au in relation to an imaginary à le.

So all in all, there is more to teaching partitives than meets the eye. But careful planning for teaching them will almost certainly assist acquisition to some extent.