Cortana works best if you use the same language for Languages (your device language), Speech language, and Country or region.
To confirm that your settings are correct or to make a change:
Open Settings . Select Time & language, and then select Language.
Check the Languages setting for your Windows display language. To get a new language, select Add a Language and then choose one from the list. It may take a few minutes for the language pack to load. For some languages you might need to manually download a speech pack. If you remove a language you can always add it back later.
Select Region, then check the Country or region setting. Make sure the country selected corresponds with the Windows Display language set in the Languages setting.
Select Speech and make sure the Speech language setting is aligned with the previous settings. If the language you want isn't available, you can add it.
Sign out and then sign back in for the new settings to take effect.
To confirm or change your language settings on a mobile device, select Settings > Time & language. To add a new language, go to Language > Add language.
Note: You can try out Cortana through the Cortana Language setting even if your language and region settings are not aligned, but Cortana's functionality will be limited. To change the Cortana Language setting, open Cortana and go to Settings > Language. Then select the language you want to try from the dropdown menu.