Sub-directory URL for default language

Hi,

I want to have a sub-directory URL for the default language same as it is for the translated language. Then choose which sub-directory the domain is opening. Is that possible?

Explanation:
So if default language is English and translated language is German, sub-directory for English should be example.com/en/, and for translated German language should be example.com/de/

The domain example.com can then be set to point either to /en/ sub-directory or to /de/ sub-directory thus enabling choice which language shows first when you open the website.

How can do that with this plugin?