Questions & Answers about Quel castello e quella montagna sono belli.
Why does the sentence use quel instead of quello castello?
The word for "that" changes its ending based on the noun it describes, acting very much like the word "the". Because castello is a masculine noun that takes the article il, the word quello drops the "lo" and becomes quel. You would only use the full quello before masculine words that start with tricky sounds like z or s+consonant.
Why do we use quella for the mountain but quel for the castle?
There is one masculine noun (castello) and one feminine noun (montagna). Why is the adjective belli masculine?
In Italian, when an adjective describes a mixed group of masculine and feminine nouns, the masculine plural form is always the default. Because there is at least one masculine thing in this group, the adjective takes the masculine plural ending -i to become belli, rather than the feminine plural belle.
I learned that sono means "I am". Why is it used here?