Questions & Answers about Gostujuća mreža radi.
Because it agrees with mreža, which is a feminine singular noun in the nominative case.
In Croatian, adjectives change their endings to match the noun they describe in:
So here:
- mreža = feminine singular nominative
- gostujuća also becomes feminine singular nominative
The dictionary form is gostujući, and here it changes to gostujuća to match mreža.
Mreža is feminine.
A very common clue is that many Croatian nouns ending in -a are feminine. That is not true 100% of the time, but it is a strong general pattern.
So in this sentence:
- mreža = feminine noun
- that is why the adjective is gostujuća, not gostujući or gostujuće