I'm confirming this issue as there does seem to be something not quite right with respect to dictionaries which are based on the English language.
If I go to about:addons | Languages, I see English (GB) and English (CA) as being installed although I have disabled the Canadian option. If I spellcheck the text box into which I am currently typing I see the following variants of English available: Australia, Canada, South Africa, United Kingdom and United States. I haven't been able to find an upstream bug that adequately describes what I'm currently seeing in Firefox 73 and probably have been seeing for some time. ** Changed in: firefox (Ubuntu) Status: New => Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1865128 Title: English US spelling dictionary appears in the languages' menu even though it's not installed To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1865128/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs