Confusion on some Russian word structure
Here are a couple of Russian word structure that can be really confusing. I was hoping some expert could help bail me out here. Thanks in advance.
ты на четвёртом этаже, да? (translation: You're on the fourth floor, right?)
why do we not say, (ты на четвёртое этаже, да?)
the same way we say (красное вино) or (красный дом)
when do we use the (OM) at the end of the word and how to use it. Please help.
The adjective (or a numeral) has to agree with the noun it is applied to, not only in gender or number, but in the case too. So, since "этаж" here is in the Prepositional case - "этаже", then "четвёртый" (not "четвёртое" since "этаж" is masculine) should be too - "четвёртом".
So, the -ом (also -ем) ending is for the masculine adjectives in the Prepositional case.