What case is "not about" a cat in? - briefly
The phrase "not about" indicates a negative relationship and typically uses the preposition "of." Therefore, "not about" a cat would be in the genitive case.
What case is "not about" a cat in? - in detail
The phrase "not about a cat" involves the use of prepositions and cases, which are integral components of grammar in languages that employ case systems, such as Russian. To understand the case involved here, we need to delve into the semantics and syntax of negation and preposition usage.
In Russian, the phrase "не о кошке" (ne o koshke) translates to "not about a cat." The preposition "о" (o) governs the instrumental case in Russian grammar. This means that when using "о," the noun that follows it should be in the instrumental case. However, the negation "не" (ne) changes this typical usage.
When we negate a statement involving the preposition "о," the noun following "не о" is not in the instrumental case but rather in the accusative case. This grammatical rule applies because the negation affects the relationship between the preposition and the noun, requiring the use of the accusative case instead.
To illustrate this, consider the affirmative sentence: "Это общая статья о кошке" (Eto obshchaya statya o koshke), which translates to "This is a general article about a cat." Here, "кошка" (koshka) is in the instrumental case as governed by the preposition "о."
Now, let's negate the sentence: "Это не общая статья о кошке" (Eto ne obshchaya statya o koshke). In this negative form, while the phrase "общая статья" remains unchanged, the noun "кошка" should be in the accusative case. Therefore, the correct form is "Это не общая статья о кошку" (Eto ne obshchaya statya o koshku).
In summary, the phrase "not about a cat" places the noun "cat" in the accusative case due to the negation of the preposition "о." This linguistic phenomenon demonstrates how negation can influence case usage in Russian grammar.