Gostaria de saber se existem mais línguas disponíveis, pois necessito de escrever em frances e como não existe corretor automático eu gostaria de saber se tem como instalar
I would like to know if there are more languages available, because I need to write in French and as there is no automatic broker I would like to know if you have and how to install
heh, “corretor” seems to be mistyped, hence wrong translation 
Hi @OziELFG!
You have omitted the information about your OS. The installation of spell checkers differs on OSes.
If you use Windows, e.g., you just need to use Windows’ Add/Remove Programs applet, select LibreOffice, choose “Modify”, and select required languages there in the Dictionaries section under Additional components in installer.
On Linux OSes, if you have LibreOffice from the distro’s package manager, you’d need to check the manager for available language packs. For instance, this is the information for Ubuntu Bionic.
Presently, there is no definitive technical answer to this question. You can install language packs into LO. They will bring dictionaries and, with the help of spell-checker(s), they can tell you if the word exists in a dictionary. Some languages (rather few) come with a grammar checker. This will tell you if the sentence looks like an original sentence according to the rules.
The tools will not protect you against word misuses, “counter-meaning”, inaccuracies, context-inappropriate usage. Syntax-side, risks are even higher: a correct sentence structure may mean the exact opposite of your intent. Sometimes, a mere omission of an apparently minor word or an addition of supposed “noise” word is enough to break semantics.
You can produce a rough approximation with the auxiliary tools, but request the help of a friend who masters the target language to “polish” the copy.
I supposed that “corretor” in the original question was intended to be “corrector”, thus I answered about spell checkers 
Totally agree about hazards using tools for different languages without being able to check the correctness of the result.
@mikekaganski:your answer is sensible, I wrote mine (slowly, pondering words) while you were typing). People usually expect too much from spelling checkers (which are better than nothing at all) not realizing the importance of grammar and “cultural” correctness. Spelling checkers fail when a misspelling is also in a dictionary and writer in the end doesn’t suspect an error if he relies solely on the tool.