Questions & Answers about Me ostamme antiikkia, jota sinä myyt.
Why is the relative pronoun jota in the partitive case instead of the basic form joka?
A relative pronoun always gets its case from its job inside its own clause. In the clause jota sinä myyt (that you sell), the pronoun acts as the object of the verb myydä (to sell). Because the selling is an ongoing action or involves an unspecified amount, the object must be in the partitive case.
Wait, is jota in the partitive case just because the word it refers to (antiikkia) is also partitive?
No, it is just a coincidence! A relative pronoun must match the noun it refers to in number (singular vs. plural), but its case is decided completely by its own clause. Here, both the main sentence and the relative clause happen to have verbs that take partitive objects, but their cases do not have to match.
Why is antiikkia in the partitive case?
The word antiikki (antique/antiques) acts like a mass noun here, meaning an unspecified quantity of antique goods. When the object of a verb like ostaa (to buy) is an unspecified amount or an uncountable mass noun, it takes the partitive case.
Could I use mitä instead of jota here since they both can mean 'that' or 'which'?