vs
QUICK ANSWER
"Primero" is an adjective which is often translated as "first", and "antes de" is a preposition which is often translated as "before". Learn more about the difference between "primero" and "antes de" below.
primero()
An adjective is a word that describes a noun (e.g., the big dog).
1. (position)
a. first
Luis fue el primer invitado en llegar a la fiesta.Luis was the first guest to arrive at the party.
2. (in time)
3. (principal)
An adverb is a word that describes a verb, an adjective, or other adverbs (e.g., to run quickly, very tired).
This means that the noun can be masculine or feminine, depending on the gender of the noun it refers to (e.g., el doctor, la doctora).
a. the best
Era el primero en matemáticas en séptimo grado.I was the best in mathematics in seventh grade.
antes de()
A preposition is a word that indicates the relationship between a noun and another word (e.g., He ran through the door.).
