vs
QUICK ANSWER
"Sobrinos" is a form of "sobrino", a noun which is often translated as "nephew". "Sobrinas" is a form of "sobrina", a noun which is often translated as "niece". Learn more about the difference between "sobrinos" and "sobrinas" below.
el sobrino()
A masculine noun is used with masculine articles and adjectives (e.g., el hombre guapo, el sol amarillo).
1. (relative)
la sobrina()
A feminine noun is almost always used with feminine articles and adjectives (e.g., la mujer bonita, la luna llena).
1. (relative)