Questions & Answers about On popłynął do domu przez jezioro.
Does popłynął mean he swam, or could he have been in a boat?
It can mean either! The verb płynąć (and its completed form popłynąć) is used for almost any movement on or through water. Depending on the context, he could have been swimming, sailing, or paddling a kayak.
Why do we need do here? Can't we just say popłynął dom for "he swam home"?
In Polish, you can't use the word for "home" as a direction all by itself like we do in English. You have to literally say "to home" or "to the house". The preposition do (to) forces the noun dom into the genitive case, which makes it domu.
I learned that przez means "through". Does it also mean "across"?
Yes! When talking about physical movement from one side of an area to another, przez translates to "across" as well as "through". So przez jezioro works perfectly for "across the lake".
Why doesn't the ending of jezioro change after przez?
The preposition przez requires the accusative case. Because jezioro is a neuter noun, its accusative form looks exactly the same as its dictionary (nominative) form. It actually is in a different grammatical case here, it just doesn't change its spelling!