switch language according to multisite language switcher plugin

So, I just started my first blog using WP. I want to have a bilingual blog english/german. I started WP with the german version, got multisite set up and installed the multisite language switcher plugin.
/ is delivering english content and /de/ the german stuff, with articles it is fine.

But (for gods sake) if you read an english article WP should use the english language for front- and backend in my humble opinion per default. If someone wants to change it – users choice is okay, but things should work automatic…

I searched the settings provided with the language switcher plugin, but it does not seem to have something to tweak it.

Can your plugin handle something like this?

I use the folder setup, an option would be subdomain – but that’s defenitely not what I want to have.

Any hints how to get it done are highly appreciated!

Kind regards from Germany,
Steffen

https://ww.wp.xz.cn/plugins/wp-native-dashboard/