You can add text-to-speech voices to Windows 10 through your PC's Settings app. Once you've added a text-to-speech voice to Windows, you can use it in programs like Microsoft Word, OneNote, and Edge.
Apart from the native language (which is English) of Cortana, it supports a lot of other languages like Japanese, Italian, Portuguese, French, German, Spanish, etc. If you want, you can change Cortana ...