Próba przekonania chłopaka do drugiego kotka

What does “jedynaczka” mean in Polish?

The couple debates a second cat by weighing what the first, Zosia, would lose: “Zosia zostaje jedynaczką” — Zosia stays an only child. Where English needs two words, Polish has one, and it’s gendered: a girl with no siblings is “jedynaczka,” a boy is “jedynak,” both built straight from “jedyny” (only, sole). Losing that status is exactly the emotional stake of the debate.

The same “jedyny” root shows up everywhere something is singular or sole: “jedyna szansa” (the only chance), “jedyny w swoim rodzaju” (one of a kind). Once you know the root, “jedynak/jedynaczka” stops looking like a special vocabulary word and starts looking like ordinary Polish grammar.