Cortana is a personal assistant application which allows users to perform local and online searches using voice commands. Cortana is set to a user's default operating system language, but the app also offers other languages, including Italian, German, Spanish, French, and Mandarin Chinese.
Changing the language settings of Cortana app is a simple process that requires the installation of the desired language pack(s) on your Windows 10 device.
How To Install New Language Packs for Cortana
To begin the process of changing the language settings, click on Start, and select the Settings option. Select the Time & Language button, and scroll to Region & Language. Here, you'll find an option called + Add Language:
Simply scroll through the list of available language, and select the language pack you would like to install:
Once you have made your selection, you will be taken back to the Region & Language menu. Select the new language pack from the list and then click on Options:
Click on the Download button located below Speech to get the speech file for Cortana:
Once the language pack has been successfully downloaded and installed, click on Set as default.
Go to back System > Time & Language > Speech. Click on the drop-down menu below Choose the language you speak with your device and then select the new language pack: