Questions & Answers about Przestałem się martwić, kiedy odkupili mój stary dom.
How does the prefix od- change the meaning of the verb here?
The base verb is kupić (to buy). Adding the prefix od- creates odkupić, which means to buy back. In this lesson's context, the od- prefix indicates reciprocating, reversing, or returning an action to its original state, just like oddzwonić means to call back.
Why do we use the imperfective martwić się (to worry) right after the perfective przestałem (I stopped)?
Verbs that describe phases of an action, such as starting, stopping, or finishing (like przestać, zacząć, or skończyć), must always be followed by an imperfective infinitive. You completed the act of stopping (przestałem), but the worrying itself was an ongoing process.
Could odkupili mean something else besides buying something back?
Why does mój stary dom look like it is in the nominative case when it is the direct object of the sentence?
It is actually in the accusative case because it is the direct object of odkupili. However, for inanimate masculine nouns like dom, the accusative form is identical to the nominative form. Therefore, the phrase mój stary dom does not change its endings.