Thread: Basic grammar questions concerning prep case and adj/noun agreement

1) Some nouns look and behave like adjectives, and числительное is one of them.
So you will need to decline these words as adjectives, for example:
-Пожарный
-Гостиная
-Числительное https://ru.wiktionary.org/wiki/%D1%8...BD%D0%BE%D0%B5


2) For some reason, we don't say "в каком дне"
"В какой день" is acceptable but rare.
I think it's a kinda set phrase, and usually you will see just "когда" instead.
There are more "exceptions", of course (and I suspect, that nouns are here in fact in Accusative):
-в первый день весны
-сын пошёл в первый класс
-в этот раз
-в кои-то веки
-в один присест
...
More examples, all escaping "в дне" thing:
- На какой день назначено совещание?
- На какую дату ты взял билеты?
- Могу устроить. Так вам на когда?
- Когда премьера?

Another tricky word you will encounter soon --
"в" + "час" = "в часу"
- в котором часу она проснулась?
But suddenly, speaking figuratively (not about specific point in time, but of some more prolonged "times"), we are again on the light side:
- в час опасности, в недобрый час, ...

Sorry on both points

Very helpful. Спасибо!