Breakdown of Oni przyszli pierwsi, my byliśmy drudzy.
być
to be
oni
they (masculine personal)
my
we
pierwszy
first
Questions & Answers about Oni przyszli pierwsi, my byliśmy drudzy.
Why does this sentence use pierwsi instead of an adverb like najpierw?
In English, "first" acts as an adverb in "arrived first". In Polish, when you mean "arrived as the first ones", you use the adjective pierwszy and make it agree with the subject. Since Oni is masculine personal plural, we use pierwsi. If you used the adverb najpierw, it would mean "firstly" in a sequence of events (e.g., "First they arrived, then they ate").
The dictionary form of "second" is drugi. Why does it change to drudzy here?
Drudzy is the masculine personal plural form. When forming this plural for adjectives ending in -gi, the g mutates to dz. You use this form because my byliśmy implies the group includes at least one man. If it were an all-female group, it would be my byłyśmy drugie.
With the verb być (to be), shouldn't the following word be in the instrumental case? Why is it byliśmy drudzy instead of drugimi?
You use the instrumental case after być when the following word is a noun or an adjective-noun phrase. However, when the predicate is just a standalone adjective, it stays in the nominative case. Since drudzy functions as an adjective describing the subject here, it remains nominative.
Since Polish usually drops subject pronouns, why are Oni and my included here?