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"When" is an adverb which is often translated as "cuándo", and "whether" is a conjunction which is often translated as "si". Learn more about the difference between "when" and "whether" below.
when(
wehn
)An adverb is a word that describes a verb, an adjective, or other adverbs (e.g., to run quickly, very tired).
A conjunction is a word that connects words, phrases, clauses, or sentences (e.g., The cat and the dog slept.).
2. (relative)
whether(
weh
-
thuhr
)A conjunction is a word that connects words, phrases, clauses, or sentences (e.g., The cat and the dog slept.).
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. no direct translation
This refers to an idiomatic word or phrase for which there is no word-for-word 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.