"Children have a plastic box."
Translation:Dzieci mają plastikowe pudełko.
I'm not convinced but the English sentence here. It just doesn't sound right to me. Its mixing plural with singular. I think it either needs definite article 'the children' at the beginning or box needs to be pluralised 'boxes' depending on what answer it is trying to provoke. 'The children have a plastic box' or 'children have plastic boxes' [Unless this is just a fragment of a sentence of course]