Breakdown of Kupię półtora kilograma sera.
ser
cheese
kupić
to buy (perfective)
półtora
one and a half (m/n)
kilogram
kilogram
Questions & Answers about Kupię półtora kilograma sera.
Why do we use półtora here instead of półtorej?
Półtora is used with masculine and neuter nouns, while półtorej is for feminine nouns. Since kilogram is a masculine noun, we use półtora.
Why is it kilograma and not just kilogram?
Words expressing quantities like półtora (one and a half) and pół (half) require the noun that follows to be in the Genitive case. For the masculine noun kilogram, the Genitive singular form is kilograma.
Doesn't 'one and a half kilos' mean more than one? Why is kilograma singular?
This is a special rule in Polish! The words pół (half) and półtora / półtorej (one and a half) always take the Genitive singular form of the noun, not the plural. So you are literally saying 'one and a half of a kilo'.
Why is the word for cheese (ser) also in the Genitive case (sera)?
Just like in English when you say 'a kilo of cheese', Polish uses the Genitive case to show this 'of' relationship. So you have a chain of Genitives: półtora makes kilogram change to kilograma, and the 'of' relationship makes ser change to sera.