No, there isn't, we just have the word "sí". In order to answer negative questions we have to make the sentence affirmative, usually by using "sí que...".
¿No te gusta el fútbol? (Don't you like football?)
¡Sí que me gusta! (I do like it!)
Good luck if you're learning Spanish ;)
English is weird. yes used to mean the same as 'jo', but now usually means 'ja'. right means 'the opposite of left' and 'correct'.
In the german language we have something similar to this: "Doch". "Doch" can be used like "Doch, ich verstehe das." (Yes of course, I understand). Or if you are in an argue you can say for example: There are no red elephants. Then you can answer: "Doch" instead of the longer "Yes, there are red elephants." "Jo" can be used in that context, too I guess.
As a native English speaker, I'm sorry to have to admit that this word has no English equivalent. We are really, really bad at negating negative questions, which is one of several reasons why "Have you not been faithful to your spouse?" is a tricky question to respond to, since either "yes" or "no" could be incriminating. "On the contrary!" is the only real way of expressing that you are faithful to your wife or husband. Usually tone helps, as well.
I Spanish class I was taught that it is the custom to always respond unambiguously to negative questions by repeating the question in the answer. Like, "No, I have never been unfaithful to my spouse." I wish there were such a custom or feature in English, because I constantly find myself asking people "No-yes? or No-no?" lol.
Wouldn't "actually" be a more accurate translation, since nobody says on the contrary. "Actually, I do understand it", "Actually, I have been faithful".
1 year edit: I've since found out 'jo' can also be used to stress things, the same way actually can. E.g. 'Det er jo kaldt ute', 'It is actually cold outside'
Really the best translation is just a simple 'yes'. It's like if someone asked you "aren't you going to walk the dog?" and you say "yes, i'm going to walk it." the 'jo' would be the 'yes' in the second sentence. The trick is that it only works as yes if someone asked you a question in a negative form, so you can't substitute it for yes everywhere.. which is how you end up with the silly sounding english sentence in this example.. but really it should just be "yes, i understand it"
What about the negation? Even though French has the oui/si distinction, answering "non" is still ambiguous. Would "Forstår du ikke det ? / Nei" always be interpreted as "No, I don't understand"?
Although now that I think of it, some of the ambiguity in French comes from the fact that one way of asking question is to phrase it as a statement (without subject verb invertion) and either use a specific intonation or a question mark to indicate that it's (mostly) a question. It doesn't feel as ambiguous with the subject verb invertion, which would work for Norwegian.
It's used when you're answering positively to a question that was asked in the negative.
Like if someone were to say "Aren't you coming to the movies with us?" or "Don't you want to go to the party?" .. you would use the word 'Jo' when responding.
The sentence with the question being asked will usually have the word 'ikke' in it.