Hello JohnTitford,

Did this stop recently, after an update maybe  ?

Would you please make sure that the automatic spell-checking isn't disabled  ?

See : https://support.mozilla.org/en-US/kb/how-do-i-use-firefox-spell-checker

Maybe you could install a dictionary :

https://addons.mozilla.org/en-US/firefox/language-tools/

Thanks so much for your trouble! Don't you just hate updates?! Such a nuisance. I have followed these instructions, but I still don't get spell check as I write. But at least I've discovered the three horizontal lines feature, top right, thanks to you. Still struggling... John

If you have done what's suggested in the article, then maybe you just don't make any spelling errors .....

I really don't know what else to suggest (so sorry .... ).

But I'm glad that you now know what those three horizontal lines are about - I always call it the '3-bar menu' (some others call it the 'hamburger menu').

Do you have a dictionary installed and selected?

You can see which dictionary is selected if you right-click in a text area and open the Languages sub menu. At least one dictionary should be installed and have a check mark to indicate that it is selected.

• open the "Add Dictionaries" link to install a dictionary if you do not have one.

The spelling checker is enabled if [X] "Check Spelling" in the right-click context menu has a checkmark.

You can look here for dictionaries:

• https://addons.mozilla.org/firefox/language-tools/

Note that you need a dictionary and not a language pack that provides string translations for the user interface.

You can check the layout.spellcheckDefault pref on the about:config page.

• http://kb.mozillazine.org/layout.spellcheckDefault

McCoy said

Maybe you could install a dictionary :
https://addons.mozilla.org/en-US/firefox/language-tools/

Dear McCoy I installed a dictionary and am now up and running. Thanks SO much! Sanity restored... John

Thanks. Solved. Phew! John

My pleasure, John - I'm glad everything's okay now.