For english speakers it doesn't make sense because you use the verb "to be" for both situation: Example 1.: "I am fine, thanks" (it's a relative response becaus if you get a headache you might not be fine and your answer will probably change for "i'm not so good" etc.) BUUUT... Example 2.: "I am black" (unless u're Micheal Jackson, this state won't ever change) So.... this is the difference between "Sto" and "sono" in italian. "sto" = the 1st example - "Io sto bene" "sono" = the 2nd example - "Io sono nero". with the unravelling of the time you'll get used to it! Hope it helps! ;)
Unfortunately not how estoy/soy in Spanish or estou/sou in Portuguese. Examples:
Io sono malato = I am sick = Estoy enfermo = Estou doente
La cucina è pulita = The kitchen is clean = La cocina está limpia = A cozinha está limpa
Siete pronti? = Are you ready? = Están ustedes listos(as)? = Vocês estão prontos(as)?