LanguageTool:
$ sudo apt update
$ sudo apt install default-jre
$ cd /your-path
# https://languagetool.org/download/
$ wget https://languagetool.org/download/LanguageTool-stable.zip
$ unzip LanguageTool-stable.zip
Vim:
call plug#begin('/home/kiyoung/.vim/plugged')
Plug 'dpelle/vim-LanguageTool'
let g:languagetool_jar='/your-path/LanguageTool-5.6/languagetool-commandline.jar'
call plug#end()