Questions & Answers about Monitor na biurku jest duży, ale laptop jest zamknięty.
Because na can take different cases depending on meaning:
- na + accusative = movement onto something
- na + locative = location on something
Here the monitor is already on the desk, so Polish uses the locative:
- biurko = desk
- na biurku = on the desk
If you said na biurko, it would mean onto the desk.
This is a case ending change. The basic form is:
- biurko = desk
But after na when it means location, the noun goes into the locative case:
- na biurku = on the desk
So the sentence gives you a very common pattern:
- biurko → na biurku
- krzesło → na krześle
- okno → w oknie
You do need to learn these changed forms, because Polish nouns regularly change depending on their role in the sentence.