Questions & Answers about Yo compro unas flores bonitas.
Why is it unas and not unos?
The word for "some" has to match the gender of the noun. Even though it doesn't end in an -a, flores (flowers) is a feminine noun. Therefore, we use the feminine plural indefinite article unas.
How am I supposed to know flores is feminine? It ends in -es!
Why does the adjective bonitas come after the noun?
Can I drop the yo and just say compro unas flores bonitas?
Absolutely! The -o ending on the verb compro already tells us that "I" am the one buying. Spanish speakers usually drop subject pronouns like yo (I) unless they want to add special emphasis.