"Buy ice cream for dessert."
Translation:Купи мороженое на десерт.
well, для only works if you are not going to eat it for dessert.
Otherwise phrases like for breakfast / for lunch / for dinner / for dessert call for a set expression, which uses на + Accusative in Russian.
It sounds to me like "на" is always used when we want to use "for" with a specific time or an event (not a duration of time). Is that right? If so, phrases like: "for the party", "for autumn", and "for the end" would all use "на". Am I understanding correctly?
Для means that an object is directed to somebody or something: подарок для меня, колесо для машины, земля для крестьян, заводы для рабочих, цветы для женщин, мороженное для детей. In most cases it can be substituted with Dative without prepostion: подарок мне, мороженное детям, etc. За (in your case) means the reason: спасибо за помощь (I'm thanking you because you helped me), награда за храбрость (you are awarded because you were brave), плата за работу (I pay because you worked), etc. "For time" construction is translated usually with на: на 5 дней.
It seems like both "десерт" and "десерта" are accepted in this sentence and I have no idea why... Could somebody explain the grammar behind this to me, please?
десерта does not work here. See my comment above. Use of Acccusative is common for all "target" usages of на
Interesting. While translating the sentence I accidentally tapped on "десерта" in the app and it took it as correct while telling me that "десерт" was another correct option...
Sure that it didn't accept it as a typo ? I've had a few errors like that accepted (thank you Duo!)
It's been a while, but I think it said "Another translation:" and not that it was a typo. It was one of those "tap the blocks" exercises, so a typo shouldn't be possible, only right or wrong blocks - or so I thought...
Typos are possible there too..I hit на десерте but duo accepted it as a typo
I did the same but it rejected the accusative with mine. Maybe the software has been updated?
What do you mean by "the Accusative"? Which word was in the Accusative?
Sorry, maybe misused the case. I mean: "na desert" like "na stol" and as opposed to "na deserte" or "na stole."
Купи=buy it (once). Покупай=buy it (everytime you see it). For example, I really love one kind of tea, but in 50% cases there is no such kind of tea in local supermarket, so my family has a rule "покупАй Этот чай всЯкий раз когдА егО вИдишь" - "buy this tea every time (when) you see it". But if I want an ice cream for пОлдник (dessert time between lunch and dinner, something like British 5 o'clock tea), I'll call my boyfriend and say "купИ морОженое, когдА бУдешь идтИ с рабОты" - "buy an ice cream when you will be walking from work".
It is partitive use of the Genitive case. Count nouns are used in plural, mass nouns in singular. This use expresses "some" amount of that stuff, the amount essentially determined by how much the person ends up buying.
I haven't gotten to the adj.spell module yet, but it appears that Мороженое is not invariable/indeclinable, so, although it acts as a neuter noun, its endings regarding case and number are determined by the rules for spelling adjective endings?
And - is it ever plural? In American English, we would never say "ice creams", but rather a phrase such as "6 kinds of ice cream" or "6 pieces of ice cream (the kind on a wooden stick)".
We treat мороженое as a mass noun and only use its singular form.
Пирожное is a count noun.
I would understand what you mean, but it would sound a bit weird to me. But, you could say к ужину/завтраку/обеду, talking about the meal That's different though, just illustrating the point.
What is "Купите?" I don't know yet how this verb is conjugated, so this appeared to be the second person plural (i.e., imperative) form.
It is completely regular, like говорить or любить. The stress pattern is the same as that of любить.
Yes, to add more detail; infinitives tend to end with the "soft sign" (ь) but imperatives (orders/commands) are either in the plural imperative (as here) if being polite or the singular imperative if being brusk.
To ask someone to forgive is извините, to order someone to forgive is извини. (Please pardon any spelling mistakes).
Robrob's comment is somewhat misleading. You were right the first time, this is plural imperative. The infinitive is купить.
P.S. You can use this site to check the declensions of words: http://www.morfologija.ru/ e.g. enter купите and you get this: http://www.morfologija.ru/%D1%81%D0%BB%D0%BE%D0%B2%D0%BE%D1%84%D0%BE%D1%80%D0%BC%D0%B0/%D0%BA%D1%83%D0%BF%D0%B8%D1%82%D0%B5
Or you can use Wiktionary. I find it a bit less convenient but it has the advantages of being in English and marking the stress.
I need to break out my copy of Barron's 501 Russian Verbs, along with Essentials of Russian Grammar, which I bought when I was still learning from a book. Should have thought of these before, as I prefer to have a reference in front of me while going through these exercises.
And if Купите is indeed imperative plural, why was this sentence an incorrect choice?
It was an exercise in which we had to pick all of the correct sentences; and I believe I picked the correct one plus the one beginning with Купите, but this was apparently wrong. I don't know why as it seemed everything was correct.
I see. The options aren't visible from the discussions, in fact I think the wrong ones are randomly generated. If it happens again that you don't know why an answer is wrong, it might be a good idea to paste the entire sentence into discussion.
That is what I should have done; I guess I assumed everyone had been given the same exercise. Future reference!
На should not needs to be used with genitiv? That is what i understood please explain me that.
Once again, duolingo accepts only their vision of Russian syntax. It's perfectly acceptable to say надо купить на десерт мороженое