Questions & Answers about Często rozmawiamy o popularnych filmach.
Why does the word for "films" end in -ach here?
Because it is in the Locative plural case. The preposition o (when it means "about") requires the Locative case. The great news is that the Locative plural is incredibly regular: almost all nouns across all genders simply take the ending -ach. So, the plural of film becomes filmach in this case.
What rule makes the adjective popularnych end in -ych?
Adjectives must match the case, number, and gender of the noun they describe. Since filmach is in the Locative plural, the adjective must be too. For most adjectives, this means replacing the standard dictionary ending with -ych. (Note: If the adjective stem ended in a soft consonant like -k or -g, it would take -ich instead).
Does the preposition o always force words into the Locative case?
When o translates to "about" (as in talking, thinking, or reading about something), yes, it always triggers the Locative case. You might occasionally see o used with the Accusative case, but only when it means "for" (such as asking or fighting for something).
Why doesn't the sentence start with the pronoun my (we)?