Breakdown of В нашей академии студенты слушают лекции об астрономии.
студент
student (m)
наш
our (наш, наша, наше)
слушать
to listen
в
in / to (direction)
Questions & Answers about В нашей академии студенты слушают лекции об астрономии.
Why do академии and астрономии both end in -ии instead of -е?
They are in the prepositional case because they follow the prepositions в (in/at) and об (about). Usually, feminine nouns end in -е in this case, but nouns that end in -ия in their dictionary form (like академия and астрономия) are a special group: they take -ии in the prepositional case.
The word лекции also ends in -ии. Is it in the prepositional case too?
No, лекции is the direct object of the verb слушают (listen to), so it is in the accusative case. For words ending in -ия, the plural form ends in -ии. Because "lectures" are inanimate objects, their accusative plural form looks exactly like their nominative plural. So while it looks identical to the prepositional singular words in this sentence, it is actually plural!
Why does the sentence use об instead of о for "about"?
The preposition о changes to об when the next word starts with a spoken vowel (а, о, у, э, и). Because астрономии starts with а, we use об to make it flow better, similar to saying "an apple" instead of "a apple" in English.
Why is there no Russian word for "to" after слушают (listen)?
In English, we "listen to" something, but the Russian verb слушать takes a direct object. You simply follow it immediately with the accusative case, with no preposition needed.