Dutch language

Hi,

I'd like to have my urls spelled in Dutch.
Now the blog address of page 2 is:
https://site.nl/page/2/
Would like:
https://site.nl/pagina/2/

Also I see category, instead of categorie.

In General Settings some months ago I changed the site language to Dutch. So the Dutch version of WP has been installed.
In my User Profile the site language has now also been changed to Dutch.

In Wp-config.php I don't see anything relevant.
Are there other factors I should consider?
Thanks for any help!