日本語は話しません nihongo wa hanashimasen Added: わかりません = I don't understand Japanese 話せません = Unable to speak Japanese 話す(speak), the stem is す, it is さ、 し、す、す、せ、せ - 話さない ( not to speak) - 話しません (not to speak) -話せません (not able to speak) The question ask " I don't speak Japanese, it is not ask I don't understand English. Additionally, using 話せません is unable to speak. He/She just don't speak Japenese, it doen't means that he/she was unable.

Hello Moon, 日本語わかりません。 nihongo,wakarimasenn

yes, cherry's answer is right, 日本語が分かりません。nihongo ga wakarimasen. or, you can say, 日本語が話せません。nihongo ga hanasemasen. but you cannot say 日本語が話しません, if you mean you're not able to speak japanese, because 話しません is another meaning, it means you won't speak japanese, it makes people think that you can speak japanese but you won't.