Questions & Answers about Czy kupujesz chleb i ser?
Why haven't the words chleb and ser changed their endings here? Aren't they direct objects?
They are direct objects, which means they are in the accusative case. But there is good news for this lesson: for inanimate masculine nouns like chleb (bread) and ser (cheese), the accusative form looks exactly the same as the dictionary form. You don't have to change them!
How does the word czy work here? Does it mean "are"?
No, czy does not mean "are". It is a special word used to start yes/no questions in Polish. Think of it as a spoken question mark at the beginning of the sentence. The "are you" part of the English translation is entirely covered by the verb kupujesz.
Where is the word for "you" in this sentence?
In Polish, subject pronouns like ty (you) are usually dropped. The ending of the verb kupujesz already tells us exactly who is doing the action. You only need to add ty if you want to emphasize it, like "Are you buying the bread?".
Does kupujesz mean "you buy" or "you are buying"?
It can mean both! Unlike English, Polish does not have a separate continuous tense. The single present tense verb kupujesz translates to "you buy" generally, or "you are buying" right now, depending on what makes sense in context.