Spanish: Either Or Neither Nor
When you wish to ask someone whether they want this thing or another or neither one, you will need to understand how to use the expressions o … o (either … or) and ni … ni (neither … nor).
Either … Or
Everyday spoken Spanish, like English, rarely uses the full "either … or" expression. Most often, people ask, “This one or that one?” without bothering with either. Nevertheless, you need to recognize the expression when you see it.
"O me dices lo que quiero saber o tendré que sacártelo a la fuerza."
Either you tell me what I want to know or I’ll have to get it out of you by force.
More commonly, you’ll hear sentences like:
"Quiero ése o el otro."
I want that one or the other one.
"¿Eres el hermano del paciente o solo un amigo?"
Are you the patient’s brother or just a friend?
There is one trick to using "o" that many writers of Spanish forget (though you tend to do it naturally while speaking). When "o" is used in front of a word that has an ‘o’ sound, the o will change to "u".
This is a similar rule to the one that requires the word "y" (and) to change to an "e" before a word that begins with an “ee” sound.
Neither … Nor
Unlike either … or, you almost ALWAYS use the full neither … nor in Spanish. This is because, whereas you can say, “I don’t want this one or that one,” in English, you have to translate the sentence into Spanish by saying, “I don’t want neither this one nor that one.” (This is the double negatives rule.)
The word ni can sometimes be used on its own before the infinitive form of a verb to mean not even.
You can also express not even with the phrase ni siquiera.