This is the 4762nd most frequent Polish word.
obserwacji
"Obserwacji" means "observation" (genitive or locative singular in Polish).
In this context, 'obserwacji' is used as a noun in the genitive case to describe the act of observation, specifically birdwatching as a hobby.
Obserwacja ptaków jest moją ulubioną pasją.
Birdwatching is my favorite hobby.
Here, 'obserwacji' appears as a noun in the genitive plural form, indicating multiple instances or acts of observation.
Do prowadzenia dokładnych obserwacji potrzebny jest teleskop.
A telescope is needed to conduct precise observations.
In this sentence, 'obserwacji' is used as a noun in the genitive singular form, emphasizing the necessity of sustained observation in the context of an experiment.