What is are the three main languages of alps?

The Alps are spread across several countries, so there isn't a single set of "three main languages".

However, here are the languages most commonly spoken in the Alpine region, grouped by country:

France: French

Italy: Italian

Switzerland: German, French, Italian, Romansh (four official languages)

Austria: German

Germany: German

Slovenia: Slovene

You could consider German, Italian, and French as the three most common languages in the Alps, as they are spoken in multiple countries.