Breakdown of Nie wiem, czy po tych zajęciach poszedł do domu.
dom
house
czy
[question particle]
nie
no / not
ten
this (m)
Questions & Answers about Nie wiem, czy po tych zajęciach poszedł do domu.
Why does the word for "these classes" become tych zajęciach after po?
The preposition po meaning "after" an event always takes the Locative case. The base word for classes is zajęcia, which is plural. Its Locative form takes the typical plural ending -ach. The word for "these" (te) must match it, changing to its Locative plural form, tych.
I learned that "if" is jeśli. Why is czy used here instead?
Polish has two different words for "if". You use jeśli for conditions, like "If it rains, I will stay." But when "if" means "whether" in an indirect question (where the answer is yes or no), you must use czy. Here, you are wondering: "Did he go home? Yes or no?"
Is zajęcia related to the word zajęty (busy)?
Yes! Zajęcia literally refers to things that keep you occupied. In Polish, it is a plural-only noun (like "scissors" in English) used to talk about university classes, extracurricular activities, or organized lessons.
Why is poszedł used here instead of szedł?
Poszedł is a perfective verb, meaning it describes a completed action. You use it here because you are talking about a single, finished trip to his house. If you used szedł (imperfective), it would mean you were wondering if he was in the process of walking home at a specific moment.