Questions & Answers about Proszę nie używać mojego mydła.
Why is it mojego mydła instead of moje mydło?
The verb używać (to use) is special because it always requires its object to be in the Genitive case instead of the standard Accusative case. On top of that, the verb is negated (nie używać), and negated direct objects also demand the Genitive case. So, the basic form moje mydło changes to mojego mydła.
How do we form the Genitive case for moje mydło?
Mydło (soap) is a neuter noun. To make it Genitive, you drop the final -o and add -a, resulting in mydła. The neuter word for my (moje) changes its ending to -ego, becoming mojego.
Why is the verb używać in its dictionary form (infinitive) here?
It directly follows the word proszę (please). A very common and polite way to make requests or give instructions in Polish is to use proszę followed by the infinitive form of an action verb. You can think of it as literally saying I ask to not use.
Why do we use the imperfective verb używać here instead of a perfective one?
When telling someone not to do something, Polish strongly prefers imperfective verbs. This is because negative commands are usually about setting a general rule or completely forbidding an action, rather than focusing on a single, specific completed event.