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"Primero" is an adjective which is often translated as "first", and "finalmente" is an adverb which is often translated as "finally". Learn more about the difference between "primero" and "finalmente" 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.
finalmente()
An adverb is a word that describes a verb, an adjective, or other adverbs (e.g., to run quickly, very tired).
1. (in the end)
a. finally
Después de años de trabajo arduo, finalmente terminaron su prototipo.After years of hard work, they finally finished their prototype.
b. in the end
Giselle dijo que no le gustaba el pescado, pero finalmente lo comió.Giselle said she didn't like fish, but in the end she ate it.