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"En" is a form of "en", a preposition which is often translated as "in". "Tren" is a noun which is often translated as "train". Learn more about the difference between "tren" and "en" below.
el tren()
A masculine noun is used with masculine articles and adjectives (e.g., el hombre guapo, el sol amarillo).
en()
A preposition is a word that indicates the relationship between a noun and another word (e.g., He ran through the door.).
