How to change system language Dell Inspiron

I’m having problems with the system (primary?) language - the language in the headings and descriptions on the display screen. I want everything to be in US-En so I changed everything in the Regional Settings (Language = en-US; Format all to en-US), and Locale (System Locales = en-US; Detailed Settings all to en-US). However, the system language is still in the local language. How do I fix this? Thanks.

Please see:

Thanks. I’m in the process of making sense of it.