Muszę pilnować psa mojej siostry, bo ten mały pies czasem ucieka z ogrodu.

I have to watch my sister’s dog, because that little dog sometimes runs away from the garden.

Breakdown of Muszę pilnować psa mojej siostry, bo ten mały pies czasem ucieka z ogrodu.

• ja: I
• pies: the dog
• mój: my
• bo: because

Questions & Answers about Muszę pilnować psa mojej siostry, bo ten mały pies czasem ucieka z ogrodu.

Why is it Muszę pilnować...? What does muszę mean, and why is pilnować in the infinitive?

Muszę means I must / I have to.

After musieć (to have to / must), Polish normally uses another verb in the infinitive:

• muszę pracować = I have to work
• muszę iść = I have to go
• muszę pilnować = I have to watch / keep an eye on

So Muszę pilnować psa... literally means I must watch the dog...

Why is it psa, not pies?

This is a very common question, because the verb pilnować takes the genitive case, not the accusative.

The basic dictionary form is:

• pies = dog

But after pilnować, it changes to:

• pilnować psa = to watch the dog

This is just how the verb works in Polish. Some verbs require specific cases, and pilnować is one of the verbs that commonly takes the genitive.

Compare:

• Widzę psa = I see the dog
• Pilnuję psa = I am watching the dog / keeping an eye on the dog

In both examples you see psa, but for different grammatical reasons. With pilnować, learners often simply memorize the pattern:

• pilnować kogo? czego? = to watch / guard whom? what?

Why is it mojej siostry? How does work in Polish?