The included French dictionary is full of misspelled words and… I encounter this problem since the very beginning (guess it was in 2000). So after 21 years, I can't imagine I'm  the only person writing French who encounter this problem.
To avoid wasting your time : it has nothing to to with the personal (added) words located in files ~/Library/Spelling/LocalDictionary and ~/Library/Spelling/fr
which I emptied completely.
nor with the fact that I know the spelling checker only checks if the word exists, and knows notting about grammatical rules.
Thank you for your time and answer.
Sincerely,
Danny LAUWER
	
		
			
		
		
	
				
			To avoid wasting your time : it has nothing to to with the personal (added) words located in files ~/Library/Spelling/LocalDictionary and ~/Library/Spelling/fr
which I emptied completely.
nor with the fact that I know the spelling checker only checks if the word exists, and knows notting about grammatical rules.
Thank you for your time and answer.
Sincerely,
Danny LAUWER