If useful for some Spanish speaker.. I think the perfective aspect of приготовить and the imperfective готовить could be similar to "tener cocinado" (which focus on the result) and "cocinar" (which focus on the action). In this example it would be "quiero tener cocinada sopa para el almuerzo".
Similarly, in English готовить can be "cook" and приготовить, "have (something) cooked". In this case it would be "I want to have soup cooked for lunch".
Hope I'm not wrong. , доброе день!
I think because this construction "for lunch," "for dinner," "for breakfast" always uses на. I think it's similar to how nouns take в или на and you just have to memorize the nouns that take на. I don't understand для very well yet. It seems very confusing to me and I avoid using it if I can find any other way around it. Sorry if that wasn't all that helpful.
I appreciate Zoe's response, and I do not disagree with it. (I have given a lingot also to her to express this appareciation.) I would, however, appreciate it if someone who is more certain of the answer to this question would make a reply. In the meantime, here is a discussion with an answer I'm going to accept: http://forum.wordreference.com/threads/%D0%97%D0%B0-vs-%D0%B4%D0%BB%D1%8F-vs-%D0%BD%D0%B0-for-for.2116549/
Now, there's a good reason to claim that the translation of "обед" could be both "dinner" and "lunch". Explanation:
In Russia, it is in customs to eat the largest meal of the day during Western European / American lunch time, which is "обед". In the evening they eat supper, "ужин". This supports the translation to "lunch".
But, this gives a false impression of having a type of meal associated to the word "lunch" in another cultural context. Russian "обед" is not a slim, squashed baguette eaten while waiting for the coffee machine to finish making a jolt of caffeine for your brain. It has the same nature than western dinner has. This supports the translation to "dinner".
In addition, by definition, the dinner is the largest meal of the day, eaten from midday to evening. The exact timing of you dinner is determined by your local customs.
Therefore, both translations are correct, depending on the point of view.
Source of information at WordReference: http://forum.wordreference.com/threads/lunch-vs-dinner.2143337/
I think it's most likely that the word "the" is unneccessary, and sounds a little unnatural. It's more common to say "I want to cook (or "make") soup for lunch." If you say "the lunch", then it sounds like you're referring to a specific event in the future, like a lunch to be served at a business conference. If you're just talking about lunch for that day, it's more common to just say "for lunch".
"Я хочу" translates to "I want", whereas "мне надо" translates to "I need" and is in dative case (necessary to me.) Therefore, "я надо" and "мне хочу" would not work, as far as I know, because the subject-verb antecedent is not in the proper case.
Please correct me if I am wrong. I am still studying Russian and not 100% sure in the accuracy of my response.
пригото́вить (prigotóvitʹ) [prʲɪɡɐˈtovʲɪtʲ] pf (imperfective гото́вить or приготовля́ть or пригота́вливать) "to prepare, to make ready; to cook" From при- (pri-) + гото́вить (gotóvitʹ), which is synchronically analysable as гото́вый (gotóvyj, "ready; finished") + -ить (-itʹ). Пригото́вить reminds me a lot of Romanian pregăti ("to prepare"), where the găti part (from gata, "ready") may be of Slavic, Paleo-Balkanic or Albanian origin.
обе́д (obéd) [ɐˈbʲet] m inan (genitive обе́да, nominative plural обе́ды, genitive plural обе́дов) "dinner, lunch" From Proto-Slavic *obědъ ("meal; lunch"), from *ob- + *ědъ (“eating”), itself from *ěsti (“to eat”).