en forme de

Question

Very 'tricky/unnatural' syntax for this 'idiom'

le gâteau était en forme de fusée ! so forme and fusée are two nouns with noun 2 acting as adjective (like 'la salle de classe). No article before first noun because of preposition 'en' which kinda fools us(well me) a bit. I tried "they made rocket shaped cakes" and got "ils ont fait des gâteaux en forme de fusée". Rockets have ONE SHAPE and thus all the cakes had that ONE shape.

I tried "they made cards in the shapes of flowers" and got "ils ont fait des cartes en forme de fleurs". Not 'formes'! Usually even behind idioms are solid grammatical truths.. I suspect this is a dumb question but does the use of 'en' in this context require a singular noun. Examples of 'not' dont come to mind... unless with a noun like 'larmes' which is really be default plural.

Accepted Answer

Hi Jameson,
The set expression 'in the shape of '  (or shaped- like ) is 'en forme de' in French.
You can add any number of words at the end,  some singular, like a rocket as you would only expect one shape or flowers in the plural.

en forme de cœur = heart-shaped 
en forme de lettres =  in the shape of letters

etc.
forme will always be singular.
Hope this helps!

Answer

être en forme de qqc. -- (lit.: to be in the form of smthg.) to be shaped likeNo, en does not require a singular noun. It is thin ice to dismantle every idiom and phrase grammatically, because often they don't follow strict grammatical rules. ...en forme de fleurs -- ... in the shape of flowers. This assumes that there's one common shape of flowers, i.e., the speaker places no emphasis on distinguishing them.