Yes and no "Ja", and the affirmative answer to "Snakker du ikke norsk?" ("Do you not speak Norwegian?") is "Jo", while the negative answer to "both" questions is "Nei". Danish, Swedish, Norwegian, Icelandic, Faroese, Hungarian, German, Dutch, and French all have three-form systems. Swedish and Danish have "ja", "jo", and "nej". Norwegian has "ja", "jo"/"jau", and "nei". Icelandic has "já", "jú" and "nei". Faroese has "ja", "jú" and "nei". Hungarian has "igen", "de", and "nem". German has "ja", "doch", and "nein". Dutch has "ja", "jawel", and "nee". French has "oui", "si", and "non". Swedish, and to some extent Danish and Norwegian, also has
Yes and no single one". (In Latin, "non" similarly devolved from "noenum", which also means "not one".) The French "oui" was formerly "oïl" (after which Langue d'oïl is named), which, in turn, came from the Vulgar Latin "hoc ille", meaning "this one" ("it is" this one). In Spanish, the words "sí" (yes) and "no" (no) are unambiguously classified as adverbs: not only do they serve as answers to questions; they also modify verbs. The affirmative "sí" can replace the verb after a negation ("Yo no tengo carro, pero él sí = "I don't own a car, but he does) or intensify it ("I