"I am looking for the thing because I need it."

Translation: Hledám tu věc, protože ji potřebuju.

[DOette]

Is it "ji" rather than "je" because "vec" is feminine?

[VladaFu]

yes

[MZ8NXF]

Nemělo by být správně česky "potřebuji"?

[AgnusOinas]

It's not too hard to find out that both forms are correct: https://prirucka.ujc.cas.cz/?slovo=pot%C5%99ebovat