vs 

QUICK ANSWER
"Either" is a conjunction which is often translated as "o", and "whether" is a conjunction which is often translated as "si". Learn more about the difference between "either" and "whether" below.
either(
ay
-
thuhr
)
A conjunction is a word that connects words, phrases, clauses, or sentences (e.g., The cat and the dog slept.).
conjunction
a. o
Either close the door or come inside.O cierra la puerta o entra.
An adjective is a word that describes a noun (e.g., the big dog).
adjective
a. cualquiera de los dos
You can choose either glass.Puedes escoger cualquiera de los dos vasos.
b. ninguno de los dos (with a negated verb)
I don't think either team will win.No creo que gane ninguno de los dos equipos.
a. ambos
There was a person on either side of me on the plane.Tenía a una persona a ambos lados de mí en el avión.
b. cada
There were beautiful ferns on either side of the country lane.Había unos helechos hermosos a cada lado del sendero rural.
A pronoun is a word that stands in for a noun (e.g., she).
pronoun
a. cualquiera
I like both of those popsicle flavors, so I can eat either.Me gustan las paletas de ambos sabores, así que puedo comerme cualquiera.
b. ninguno (with a negated verb)
I don't like beef or chicken sandwiches. I don't want either.No me gustan los sándwiches ni de carne ni de pollo. No quiero ninguno.
An adverb is a word that describes a verb, an adjective, or other adverbs (e.g., to run quickly, very tired).
adverb
a. tampoco (with a negated verb)
I don't like cockroaches either.No me gustan las cucarachas tampoco.
Copyright © 2025 Dictionary Media Group, Inc.
whether(
weh
-
thuhr
)
A conjunction is a word that connects words, phrases, clauses, or sentences (e.g., The cat and the dog slept.).
conjunction
a. si
I don't know whether I am going to do it today or tomorrow. No sé si lo voy a hacer hoy o mañana.
a. si
I'll try to find out whether she's at the office.Voy a tratar de averiguar si está en la oficina.
a.
This refers to an idiomatic word or phrase for which there is no word-for-word translation.
no direct translation
Alicia has made up her mind - she'll resign, whether or not she gets this other job.Alicia se decidió: va a renunciar, consiga o no el otro trabajo.
Whether you like it or not, I will buy this shirt.Te guste o no, me voy a comprar esta camisa.
Copyright © 2025 Dictionary Media Group, Inc.