Students with special needs can be successful in the world language classroom with the appropriate instructional accommodations and modifications.
Check out the information listed below.
Articles and resources:
http://www.onlineeducationdegrees.com/resources/teaching-foreign-language-with-learning-disabilities/
Article with strategies:
http://www.ldonline.org/article/22725/
Website with a focus on teaching language to special needs students:
http://www.languageswithoutlimits.co.uk/