I first installed the latest version 5.4.2.2 x64, then I installed the 64 bit version of java, and then I installed the language tool extension. I have selected specific grammar options in the language tool, but it is not checking for those grammar rules. Did I do something wrong? I have Windows 10 64 bit pro edition.
Grammar checking is a very complex task which is strongly linked with the language structure. As a consequence there is no “universal” grammar checker. LO offers a standard interface for checkers, such as option settings, but delegates the real job to the checker.
Grammar checkers may be provided by a langage pack but very few do. Look also in the various extensions contributed by users and developers.
From a quick search through the library, try LanguageTool (several languages), Orthos (Greek), but I have no experience with them. Translation tools may also help but I’ve been rather disappointed by the results and look-and-feel.
The topic starter seems to use exactly LanguageTool. But given the fact that he/she can’t even correctly write its name, I guess, the problem is much more serious.
(I never used such a tool, and I don’t know if the usage with LibO is wide-spread.)
‘LanguageTool’ (LT) is not a project of ‘The Document Foundation’. It is (mainly?) supplied by two individuals.
However, there is also a forum on ‘LanguageTool’ (LT) and there you can search (e.g.) for “LibreOffice”. You will get relevant matches.
Just a faint hunch: Did you install the LibO version? Is your installed ‘Java’ version sufficient?
(I do not know if/how the desktop version will cooperate with LibO.)