Questions & Answers about Las flores son rojas y bonitas.
Why do the words for "red" and "pretty" end in -as (rojas, bonitas)?
They are describing flores (flowers), which is a feminine, plural noun. In Spanish, adjectives must change their endings to match the gender (masculine/feminine) and number (singular/plural) of the noun they describe. Since the default dictionary forms are rojo and bonito, we change the -o to -as.
How can I tell that flores is feminine? It doesn't end in -as.
What would this sentence look like if there were only one flower?
It would be La flor es roja y bonita. Notice how every single word has to change to its singular form: las becomes la, flores drops the -es, the verb son changes to es, and both adjectives drop their final -s.
Why is the verb son used here instead of están?