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"Que" is a form of "que", a conjunction which is often translated as "that". "De" is a form of "de", a preposition which is often translated as "from". Learn more about the difference between "que" and "de" below.
que(
keh
)A conjunction is a word that connects words, phrases, clauses, or sentences (e.g., The cat and the dog slept.).
a. that 
Tenga en cuenta que algunas de estas características son diferentes.Note that some of these characteristics are different.
a. than 
Es más barato comprar el libro en la librería que comprarlo online.It's cheaper to buy the book in the bookshop than to buy it online.
Mi hermano es más alto que yo.My brother is taller than me.
b. to 
Prefiero las tiendas pequeñas que los grandes supermercados.I prefer small stores to big supermarkets.
A pronoun is a word that stands in for a noun (e.g., she).
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).