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"De" is a form of "de", a preposition which is often translated as "from". "Su" is an adjective which is often translated as "his". Learn more about the difference between "de" and "su" below.
de(
deh
)A preposition is a word that indicates the relationship between a noun and another word (e.g., He ran through the door.).
a. no direct translation
This refers to an idiomatic word or phrase for which there is no word-for-word translation.
Te recojo en el coche de mi padre.I'll come get you in my father's car.
¿Esa no es la casa de Susana?Isn't that Susana's house?
a. no direct translation
This refers to an idiomatic word or phrase for which there is no word-for-word translation.
Voy a comprar otro traje de baño para el verano.I'm going to buy another bathing suit for the summer.
Se usa la palanca de cambios para cambiar las marchas.You use the gear shift to change the gears.
a. with
Me sorprendí llorando de pena al pensar en él.I caught myself crying with sorrow when I thought of him.
A feminine noun is almost always used with feminine articles and adjectives (e.g., la mujer bonita, la luna llena).
su(
soo
)An adjective is a word that describes a noun (e.g., the big dog).
a. his (masculine) (singular)
A word or phrase that is masculine (e.g., el libro).
A word or phrase that is singular (e.g., el gato).
¿Hiciste su tarea por él?Did you do his homework for him?
b. her (feminine) (singular)
A word or phrase that is feminine (e.g., la manzana).
A word or phrase that is singular (e.g., el gato).
¿Sabes dónde está el cargador de su teléfono?Do you know where the charger is for her phone?
c. its (singular)
A word or phrase that is singular (e.g., el gato).
Esta es su perrera.This is its doghouse.
2. (formal) (possessive; second person singular)
A word or phrase used to refer to the second person formal “usted” by their conjugation or implied context (e.g., usted).