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"Estanque" is a form of "estanque", a noun which is often translated as "pond". "Piscina" is a noun which is often translated as "swimming pool". Learn more about the difference between "piscina" and "estanque" below.
la piscina()
A feminine noun is almost always used with feminine articles and adjectives (e.g., la mujer bonita, la luna llena).
el estanque()
A masculine noun is used with masculine articles and adjectives (e.g., el hombre guapo, el sol amarillo).
