We wrote in detail about how we picked the words here: http://cleverdeck.com/blog http://cleverdeck.com/blog. Most of the example sentences were hand-picked fr

We wrote in detail about how we picked the words here: http://cleverdeck.com/blog http://cleverdeck.com/blog. Most of the example sentences were hand-picked from tatoeba.org. That covered about 2700 of the words - our teachers wrote the remaining 300 or so.