In most ordinary contexts, the French verb savoir means “to know (a fact, or how to do something)”. Likewise, connaître means “to know (someone), to be familiar with”. IIRC, Spanish saber and conocer, respectively, work the same way.
What I’m wondering about, though, is how idiomatic uses of “know” are translated from English into French and Spanish.
Here are some sample phrases:
You know … Mary really is friendly.
You know what? You can leave right now and walk home!
Well, nobody wants to have surgery, you know?
Yeah, he’s the boss, but not the boss … you know what I mean?
Oh yeah? Well, know this – step onto my property again and I will see you in court.
In cases like these, how does one know which verb to use in French or Spanish translation? Or are there alternate contructions in French and Spanish that eliminate the need to directly translate the idiomatic “know”?
When idiomatics are involved, it’s a case by case issue. There won’t be a single word which will translate all the idiomatic uses of a foreign words. Actually, quite commonly, there’s no equivalent at all for a given idiomatic.
So, I can answer to your question for the actual examples you gave, but it doesn’t mean you can extrapolate to other idiomatics including the word “know” in english.
Savoir : Tu sais…Marie est vraiment…err…another problem…there’s no accurate translation for “friendly”…maybe sympa would do the trick, though it has a somewhat different meaning (and there’s no english accurate translation for “sympa”, either).
2)Savoir : Tu sais quoi? Tu peux partir tout de suite et rentrer chez toi (no exact translation for “home”, either, as you might know)
3)Savoir : Ben…personne ne veux subir d’intervention chirurgicale, tu sais…(note that the sentence isn’t in the interrogative form, but in the the affirmative. Actually, it’s the same sentence than your example 1), with “tu sais” at the end of the sentence instead of the beginning. “You know?” ending a statement isn’t used in french.
4)Nor "savoir nor “connaitre”, but “comprendre” (to understand) :
Ouais…c’est le patron mais pas * le patron *…Tu comprends ce que je veux dire?
5)Theorically “savoir” : “Ah oui? Sache-le…entre chez moi de nouveau et nous nous reverrons dans un pretoire/devant un tribunal” but you’re extrememly unlikely to hear such a sentence which sounds quite old-fashionned. In such a situation, people would use “ecoute-moi bien” (listen to me), for instance, or something similar.
The problem with idiomatics is that they’re just that : idiomatics. So, you can’t expect to use the exact same words in a foreign language, and not even that an equivalent is existing at all. For instance, there’s no need to ask whether one should use the french word “asseoir” to translante “sitting on the fence”, because this sentence, translated in french would just mean to actually sit on an actual fence. Similarily, and to keep your example of “know”, would you translate the french “savoir vivre” by “to know how to live”? In case you’re wondering, the answer is definitely no.