"Ho un ragno."
"ho un ragno" means, "i have a spider", but can't it also mean "there is a spider"? if so, why isnt it an optional answer? and another thing. why ragno pronounced as "ranio"?
Well, for your second question, in Italian, when you have a "gn" before a vowel, it is pronounced ni as in "news". I will let someone more experienced explain it more. As for your first question, I don't think it could mean "There is a spider". I would think that would be something like "C'è un ragno".