Breakdown of Część mieszkańców wyjechała, zanim zmniejszył się przyrost.
się
oneself
wyjechać
to leave / to go away (by vehicle)
zanim
before
zmniejszyć
to reduce
Questions & Answers about Część mieszkańców wyjechała, zanim zmniejszył się przyrost.
Why is the verb wyjechała in the feminine singular form when it refers to a group of residents?
The verb is agreeing grammatically with the word część (part/some), which is a feminine singular noun. When you use partitive subjects like część, większość (majority), or połowa (half), the verb must match this noun, taking the third-person singular feminine form in the past tense. It completely ignores the genitive plural noun (mieszkańców) that follows it.
Why is the verb placed before the subject in the phrase zmniejszył się przyrost?
Polish has flexible word order, and placing the verb before the subject is very common in subordinate clauses to improve sentence rhythm. It also helps position the reflexive pronoun się naturally. While you could perfectly well say zanim przyrost się zmniejszył, putting the verb first prevents się from awkwardly dangling at the end of the clause.
Why are both wyjechała and zmniejszył się in the perfective aspect?
The perfective aspect shows that both actions were fully completed in the past. The residents finished leaving, and the growth definitively decreased. The conjunction zanim (before) very often links two perfective verbs in the past tense to establish a strict sequence of events: one completed action happened prior to another completed action.
Does przyrost just mean "growth" in general, like a plant growing?