For example, research for JSL learners' errors mainly focus on Japanese case particles (Oyama and Matsumoto, 2010;Imaeda et al., 2003;Nampo et al., 2007;Suzuki and Toutanova, 2006), however they focus only on case particles whereas we attempt to correct all types of errors.
real JSL learners' writing contains not only errors of Japanese case particles but also various other errors including spelling and collocation errors.