Will LanguageTool support Thai language? What's the plan? Thanks!
There are no plans. New languages are supported when someone shows up, adds support for that language, and commits to maintain the language support long-term. Technical details are documented at http://wiki.languagetool.org/adding-a-new-language.
I want it use spell check dictionary. so others may not important.
Are you working on this? I have some schools teaching Thai to foreigners in Thailand who may be interested.