Hello, dear student!
Today I would like to talk about the correct usage of nouns in combination with the verb "просить" [prasit'] (ask) in Russian. The point is that this verb requires two cases after itself , i.e. a noun can be as in accusative case as in genitive one. So how should we know, which case to use and how a word changes? This rule will be a little bit difficult for a beginner, that's why if you are not familiar with the parts of speech and with cases in Russian, we highly recommend you to read and familiarize yourself with the previous articles devoted to this topic. Those who are already good at Russian, probably, know that if we are talking about abstract concepts i.e. nouns which we cannot count, sell and touch (e.g. любовь [l'yubof'] - love, спасение [spas'eniye] - salvation, воля [vol'ya] - will, счастье [shchast'ye] - happiness, защита [zashchita] - defence, etc.), we use an object (subordinate part of the sentence) as a noun in genitive case (with the question "чего?" - what?) after a verb in a sentence.
If you ask for something specific or indicate measure or quantity of something, you should use accusative case (the question "что?" - what?) after the verb "просить" [prasit']. For example, compare:
Прошу прощения (Прошу чего? прощения - Beg what? pardon) - genitive case [Prashu prascheniya] - I beg your pardon
Прошу стакан воды (Прошу что? Стакан - Asking for what? A glass) - accusative case [Praschu stakan vady] - I am asking for a glass of water.
The presence or absence of an object doesn't matter here:
Просить (у сестры) прощения/ молока/хлеба (чего?) [Prasit' (u sistry) prascheniya/malaka/ khl'eba] - To ask (my sister) to forgive me, to ask for some milk, some bread.
Просить (у сестры) ручку/ пакет молока (что?) [Prasit' (u sistry) ruchku/paket malaka] - To ask (my sister) for a pen, a package of milk.
The same is about the word "спасение" [spas'eniye] (salvation). Try to change the meaning and use it in genitive and accusative cases.