"He cooks the food."
No worry, it is Duo-correct to say "il cuisine la nourriture", but my comment was that we would not use "nourriture" when it comes to preparing food for humans, because there is a range of better words for that: le déjeuner, le dîner, le repas, le plat... (lunch, dinner, meal, dish...)
But is «cuisiner» a transitive verb, or is it an ergative verb, as it is in English?
In English, "cook" is typically a transitive verb. You need a direct object, you have to be cooking something. "I cook the chicken," "They are cooking the meal," etc.
If there's no direct object, then the subject becomes the thing that's being cooked, not the thing that's cooking something else. "It is cooking" means some food is being cooked; "it" doesn't refer to a cooker, but a cookee.
So how does «cuisiner» work in French?
Doesn't it require that you cook something? Or can you really just say, "He cooks" in French and have it refer to someone cooking instead of something being cooked?
Here's a test case: In English, "The chicken is cooking" means that someone is cooking a chicken. In French, does «Le poulet cuisine» mean the same thing, or does it mean that an anthropomorphic chicken is cooking something else? :D
Ok I understand your point.
"cuisiner" is both transitive and intransitive and a human action:
- je cuisine le dimanche (I cook on Sundays)
- je cuisine le poulet, les légumes, etc.: it is about preparing a dish, adding ingredients, following a recipe, not only heating it.
"cuire" is also both transitive and intransitive, but the meaning and the construction may change:
- je cuis sans mon chapeau (I am very hot without my hat)
- je fais cuire le poulet (I put it in the oven or the pan)
At last "le poulet cuisine" does not work, we would say "le poulet cuit". "Un plat cuisiné" = a cooked or prepared dish.