Huh? equivalent in Spanish
If someone said something in English to a Spanish speaker and the Spanish speaker was confused and had no idea what was being said, what word would they use? Is it que? An informal type word is preferred.
You can say "¿Cómo'" (universally accepted) or "¿Mande'" (in Mexico)
That's the Spanish way of saying "Huh? Come again'"
I know first hand that if you are in Spain, the correct and polite way to say "huh'" or what? is to say "Como'" So if you don't understand what someone has said or is talking about then just reply with "como'"
formally he could say "dispense pero no entendí lo que acaba de decir" but informally he would probably say qué? or como'