[Grace Themes]

Hi Giampaolo,

You can use qTranslate X WordPress plugin in your website to support for multilingual.
Your default language will remain in italian.

Install Plugin qTranslate X from WordPress plugin.
https://wordpress.org/plugins/qtranslate-x/

Used following code for making text translate ready :
[:it]Italian Text[:en]English Text[:]

Viewing in Italian used website url : http://www.yourwebsiteurl.com/it/
Viewing in English used website url : http://www.yourwebsiteurl.com/en/

Please check the link to set the default language
https://wordpress.org/support/topic/setting-default-language

Regards
Grace Themes