This is the 8376th most frequent Polish word.
piotrem
"Piotrem" is the instrumental case of the name "Piotr," meaning "Peter" in English.
Here, 'Piotrem' is used in the instrumental case, indicating the person I communicated with.
Rozmawiałem z Piotrem o jego nowym projekcie.
I talked with Piotr about his new project.
Again, 'Piotrem' is in the instrumental case, emphasizing companionship or association.
Piotr jest dobrym przyjacielem, zawsze chodzę na spacery z Piotrem.
Piotr is a good friend; I always go on walks with Piotr.
In this sentence, 'Piotrem' is instrumental, ensuring the focus on collaborative effort with Piotr.