This is the 7203rd most frequent Polish word.
jarosławem
"Jarosławem" is the instrumental case of "Jarosław," a Polish masculine proper name.
The word 'Jarosławem' is in the instrumental case, indicating the person with whom the action (talking) was performed.
Rozmawiałam z Jarosławem o jego podróży.
I talked with Jarosław about his trip.
Here, 'Jarosławem' in the instrumental case describes the person involved in the meeting at the conference.
Spotkałam się z Jarosławem na konferencji.
I met with Jarosław at the conference.
The word 'Jarosławem' in the instrumental case indicates companionship during the activity of working on a project.