Though, and this might just be me, but I've had trouble confusing them in the past. As in someone would speak in Italian and I would respond in Spanish. Then again this might just be me.
Italian and spanish share similarities in numbers,colours,dates ect. because both are Romance languages derived from latin. Rome sent colonists to its new, Hispania, province after defeating many Iberian tribes. The eastern roman empire called it Espana, after making a settlement in the south eastern side in 6oo AD. That is how the similarities with Spanish and Italian work. Since Rome was in Italy and the Eastern Roman Empire traversed italian peninsula in 600 AD to clear out Barbarian invaders you can sense an historical association right away . If you are interested in this make sure you learn about the history of the country and learning will be more fun.I heard that Italian is a little similar to Spanish. Is this true? If so, maybe learning Spanish wouldn't be too difficult.