Russian Language Stack Exchange is a question and answer site for students, teachers, and linguists wanting to discuss the finer points of the Russian language. It only takes a minute to sign up.
Sign up to join this community
"Мы в трёх часах езды от Бостона."
I came across this sentence in Russian, and it seemed wrong to me. I would have expected час to either be in genitive singular case (часа) since we have the numeral трёх before it, or perhaps singular prepositional (часе) because of the в.
Can someone help me figure out how to correctly deconstruct this sentence from a case perspective?
Whenever you need to figure out case, just look to the preposition as a guide. For instance, the preposition в is only used with the accusative and prepositional cases, not with the genitive.
В трех часах езды - refers to a measure, a degree (of time, space, quantity). The word час here indicates not the astronomical time, but how far away the object is in distance.
Similar phrases: в километре от станции, в трех минутах ходьбы, съесть в большом количестве, рассказать в двух словах.
The genitive singular is used after the numerals два, три, четыре and оба only when the numeral is in the nominative or the accusative case. For all the other cases, both the numeral and the following noun take that case (with the noun in the plural):
N. три часа
G. трёх часов
D. трём часам
I. тремя часами
P. трёх часах
In your example both words are in the prepositional case because they're governed by the preposition «в».
See this declension tool when in doubt.
