I have a list of 1860 progressively more difficult sentences in English and in Polish. The original source is: http://www.apronus.com/polishlessons/lekcje.htm
I am also adding them to my project: http://www.cucumis.org/project_1_p/project_v_188.html
The goal is to translate them into as many languages as possible for use as a learning aid.
I would really appreciate it if anyone wants to help.