This is the 15922nd most frequent Polish word.
tlenu
"Oxygen" (genitive form in Polish).
Here, 'tlen' is used in its nominative form to refer to the element oxygen.
Rośliny wytwarzają tlen podczas fotosyntezy.
Plants produce oxygen during photosynthesis.
In this sentence, 'tlenu' is used in the genitive case, indicating oxygen as an essential substance needed for breathing.
Potrzebujemy tlenu, aby oddychać.
We need oxygen to breathe.
'Tlenu' appears in the genitive case, being used in the context of absence or lack, focusing on oxygen as a missing element.