baseball cap, tennis racquet, door knob

Question

Could you add some clarification re: wedding bells, baseball cap, tennis racquet, door knob, golf club, soccer ball, soccer field, sunglasses, Christmas tree, water tank, bus stop, fire truck, etc.

By your lesson, these should all be “à” (what something is designed for), but in fact this whole genre is “de”.

Specifically, why is it “boîte à bijoux” and not “boîte de bijoux” ? Other than convention.

Clearly, these are not just a few exceptions, but an entire class of compound nouns (open form, noun+noun) that is not covered in the lesson.

Thank you.

Accepted Answer

Hi David, 
There are different types of compound nouns and the lesson specifically concentrates on those which take prepositions.
You might find useful reading my following answer to a similar question which lists some using a hyphen -
https://french.kwiziq.com/questions/view/are-these-examples-of-compound-nouns
In the case of 'boîte à bijoux', normally when you can say - for something - it will be 'à' in French as in:
Cuillère à soupe, brosse à dents, verre à vin
But I am sure there will be some exceptions!
Hope this helps!

Answer

Thanks Cécile. C'est possible que vous ne dormez jamais ? Ou au moins, levez vous un peu plus tard dans le weekend. Mais ...

While your answer works for boîte à ... and brosse à ... and cuillère à ...

"when you can say - for something -" seems to apply to all my examples just as well.

Are there any general rules or guidelines for à vs. de with noun+noun constructions ?

I guess most of my prior learning and examples were sports related, which all seem to be "de".

Answer

Re-bonjour David!
Effectivement,  je suis 'une lève-tôt' mais je dors suffisamment, ne vous inquiètez- pas...
Le contraire est 'un/e couche-tard'
Revenons à nos moutons -
There are no rule, just categories as far as I am aware but it would be good to develop the lesson as this has been asked before.
We are all so inundated with work that it wont happen anytime soon.
It is so odd that we say -
un arrêt d'autobus but le centre-ville.
Grévisse says that it is mainly the preposition 'de' which is used but you can have other prepositions like 'à, autour, contre par, pour, sans' etc.
une planche à dessin = a drawing board
un sirop contre la toux = a cough mixture
but 
un cor de chasse = a hunting horn
etc.
Hope that helps!