How to turn on Alexa's multilingual mode and use it

Amazon offers a multilingual mode for Alexa devices. In the US, it allows Alexa to switch between English and Spanish. For instance, if you have Alexa set to English, yet ask a question in Spanish, Alexa will either respond in Spanish or ask if you want to change your language settings.

Source : https://www.pocket-lint.com/alexa-multilingual-mode-how-to-use/