VI. Masculine Virile Nouns Ending in –a
by E. Małachowska-Pasek
and E. Wampuszyc

-y ending
Often, masculine virile nouns terminating in -ga, -ra and –ca take the -y ending. These nouns may undergo alternations in the stem.

Here is a partial list of these nouns:

Note that the morphological ending -ca is often used in nouns that refer to persons performing an action (kierowca - driver, sprzedawca - sales person)

UWAGA! There are many exceptions to the above rules, particularly if the word has negative connotations and can refer to either a man or a woman (e.g., niedołęga - niedołęgi (oaf).

-i ending
Masculine virile nouns ending in -ta take the -i ending and undergo the alternation t> ć/ci and st> ść/ści. Often, these words are cognates to English.

Here is a partial list of these nouns. Try forming the plural on your own.