The question: No?
Why do spanish-speaking people always say "No?" after they say something or ask a question?
For ex.: "Es muy intersante! No?"
Why not "Si?" or just ask the question?
16 Answers
In English this is called Question Tag. If the sentence is in the positive, then question tag is negative and vice versa.
We are not going, are we? We should be going, shouldn't we?
Same goes for Spanish.
Nos vamos ya, ¿no?
No deberíamos irnos o ¿sí? (less commonly used)
Why do we say Isn't it? Is that not so? Why do we use the negative?
Is that so? Positive or negative, both are understood. I believe the same to be true in Spanish. One is just more common that the other.
It is a wonderful and brief way of continuing the conversation.
because:
It is a verbal invitation for the other party to respond to their comment!
They can use ¿sí? just as easily, and there are several equivalents in English...right, isn't it, ain't he, didn't he, and stuff like that.
He's going to the store, ain't he? (Va a la tienda, ¿sí / no?)
He just got a new car, didn't he? (Acaba de comprar un coche nuevo, ¿sí / no?
They're vacationing in Spain, right? (Están de vacaciones en España, ¿sí / no?)
.
More info on ain't. Please note that "ain't" should never be used in formal writings or in discussions with business people that you would like to impress. It sounds uneducated in those settings.
La palabra "ain't" nunca se usaría en documentos formal o en conversaciones con personas de negocios a las que quieren causar buena impresión. En esas situaciones suena inculto.
There is no reason other than "that's how they do it." Sorry. 
I'd like to offer my best explanation, and thus being... saying "¿no?" at the end is like asking if the person agrees. You will also hear, "Es muy interesante, ¿verdad?" This in my opinion is the more proper way of phrasing it. However for some it's just easier to say "¿no?" at the end, because all spanish speakers understand this is a way of getting the other person's view/opinion on the matter. Hope that helps.
-DJ Huero ((( d(-_-)b )))
I'm surprised that although a few people have drawn parallels with the negative affirmations that we bung on the end of sentences in English, no one has noted that we do exactly the same.
How do you like the full English breakfast? Good no?
It's really interesting no?
Y vainas así.
Why do spanish-speaking people always say "No?" after they say something or ask a question?
We are pretty weird, are we not? (also: aren't we?)
Well I think they do it because that's the way they do it. We do some pretty crazy stuff in English but don't think a thing about it because we were raised talking that way. I think the same is true with those who speak other languages.
Around here, people tend to say "¿Sí o no?" a lot.
Because Spanish people are naturally a negative bunch.... they're soooooo pessimistic about life, that it's unbelievable! 
In Spanish "no?" in the end it's like The Question Tags in English
Could be that i is jus well down wiv da kids, innit..
That's extremely funny!!! Hehehe........maybe you're just young at heart.
I think you get pretty much the same meaning if you say: ¿es tuyo, verdad? or ¿es tuyo no?
I use it with frequency Seb, Oxford educated an' all, I am Welsh mind but don't think that to be relevent, I'm sure I'm not the only one..
I use 'isn't it', at the end of my sentences, sometimes. But 'no', is a new concept to me.......maybe it's a generation thing.
