Here’s how you can enable automatic spelling and grammar check as you type in LibreOffice Writer.
LibreOffice Writer supports dictionary which is used to validate the grammar of the words as you type. Writer shows red color curved line under incorrect word in the document after it validates against the supported dictionary.
How to Enable
There are two ways to check the spelling and grammar. A) Manual mode and B) Automatic Mode as you type.
To enable the automatic spelling and grammar check, go to Menu Tools → Options. From the left side menu, select Language under Language Settings. Make sure to choose appropriate language under “Default Languages for Documents” – Western: English (USA).
Go to Writing Aids Option to the left and under options choose ‘Check spelling as you type’ and ‘Check grammar as you type’.
Now you can see red curly underline on words which has spelling/grammar errors.