This is how u say it in spanish: que quieres saber?
Translation: Sabes español?
¿Sábes qué? = Do you know what?
¿Me conoces?
i didn't know that you speak spanish = no sabía que hablas español.
Yeah, I do...lol did you mean, How do you say, you know lots of Spanish? If that's the case, then you say,"Sabes mucho español".
Do you know about that is: Sabes de eso
how to say,you must know your child's weight or age in spanish.
No sé.
No sé
¿Me conoces?
Te conozco