The collective numerals "двое", "трое" ... "семеро" are used with ... .
the Genitive singular.
the Genitive plural.
the Nominative plural.
the Dative plural.
In the Dative, Instrumental, Genitive, Accusative animate and Prepositional cases ... .
the noun stays in the Genitive case.
they agree in gender in number with the noun.
The use of collective numerals is obligatory with personal pronouns, when the nouns don't have singular form or are used and pairs, with the word "дети" and ... .
when we talk about a group of people without using a noun.
when we talk about a group of people using a noun.
The use of collective numerals is optional when we speak about baby animals and ... .
persons of masculine gender.
persons of feminine gender.
You can't use collective numerals with persons ... .
of masculine gender only.
of feminine gender only.
"Вдвоём", "втроём", "вчетвером", "впятером", "вшестером", "всемером" are used when ... .