Questions & Answers about Ja byłem w parku w zeszłym roku.
Why is ja included if the verb byłem already indicates the subject?
In Polish, subject pronouns are optional (pro-drop language). You can drop ja because byłem (I was) shows 1st person. Including ja adds emphasis, like as for me, I was in the park last year.
What does byłem mean, and what is its grammatical form?
Byłem is the masculine 1st person singular past tense form of the verb być meaning to be, in the imperfective aspect. It literally means I was. A female speaker would use byłam.
How would a female speaker express this sentence?
Why is the phrase w parku used here, and what case is parku?
W meaning in requires the locative case. Parku is the locative singular of park. So w parku means in the park.
Why is zeszłym spelled with -ym, and what case is ?