I've been learning Spanish for four years in school. Recently, I've started learning Italian via Duolingo. Does the fact that I use different methods of learning reduce the possible mixup of the languages?
Yes, learning via different methods helps reducing mix-ups. Take a look at this related question How can I avoid confusions when studying two similar languages?.
I am quoting Quill's answer here,
If you race cars, you might not have trouble driving normally, unless your brain can't differentiate the two similar environments.
I always found good ways to differentiate two similar things was to learn them in a different way:
- Flash cards vs Memory match (Associating mental reflection of events with terms)
- Red cards vs Green Cards (Associating colours with words)
- Study room vs Backyard (Associate locations and location-based stigma with terms)
His answer essentially means that learning two languages by different methods will help us differnetiate each languages where mix-up occurs.
However if one the languages is your native lanuage then there are high chances that a mix-up occurs irrespective of the method you learn.
This isn't a neurological or biological answer, though I'd be interested to see one. This is my opinion, strictly speaking.
In my opinion, ultimately it won't make a difference. Or rather, as your knowledge of Italian and Spanish progress to a higher-advanced level, it won't make a difference.
On the other hand, it may reduce the cognitive conflict you experience as you are learning both languages. The way you learn both languages will be different and consequently the way you remember both, will be ever so slightly different.
As you gain practical experience and a degree of fluency, if you choose to pursue both languages to that extent, then the differences you had when learning them will vanish.
As a result of learning them in distinct ways, you might keep them separate for a while, but if you gain a comfortable fluency in each language, then it will eventually be altogether the same.