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