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"El lobo" is a form of "lobo", a noun which is often translated as "wolf". "Pedro" is a proper noun which is often translated as "Peter". Learn more about the difference between "el lobo" and "Pedro" below.
el lobo(
loh
-
boh
)A masculine noun is used with masculine articles and adjectives (e.g., el hombre guapo, el sol amarillo).