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"En" is a form of "en", a preposition which is often translated as "in". "Coche" is a form of "coche", a noun which is often translated as "car". Learn more about the difference between "en" and "coche" below.
en(
ehn
)A preposition is a word that indicates the relationship between a noun and another word (e.g., He ran through the door.).
el coche(
koh
-
cheh
)A masculine noun is used with masculine articles and adjectives (e.g., el hombre guapo, el sol amarillo).
1. (vehicle)
a. car 
Mi coche no prende porque tiene una falla en el motor.My car won't start because of a problem with the engine.
3. (train car)
a. car  (United States)
Regionalism used in the United States
Tu mamá y yo vamos a pasar al coche comedor para almorzar.Your mother and I are going to the dining car to have lunch.
b. coach  (United Kingdom)
Regionalism used in the United Kingdom
Según nuestros boletos del tren, nuestros asientos están en el coche F.According to our train tickets, our seats are in coach F.
c. carriage  (United Kingdom)
Regionalism used in the United Kingdom
Los coches del tren tienen aire acondicionado y asientos muy cómodos.The train carriages have air conditioning and very comfortable seats.
4. (for babies)
a. stroller 
La niñita no se quería subir al coche. Quería ir caminando.The little girl didn't want to get in her stroller. She wanted to walk.
b. carriage  (United States)
Regionalism used in the United States
Paseaban por el parque con el bebé en su coche.They were taking a stroll through the park with the baby in her carriage.
c. pram  (United Kingdom)
Regionalism used in the United Kingdom
Rocío quiere un coche doble para pasear a sus gemelos.Rocio wants a double pram to go for walks with her twins.