In Polish lesson 3 there is a mistake. Ile jest mleka w lodówca. This should be “Ile jest mleka w lodówce”
The place to post about mistakes in the Polish courses by memrise is here:
http://community.memrise.com/t/course-forum-polish-1-7-by-memrise/7962/39
I have already posted a screenshot of your post there, so you don’t need to post it again, but for future reference, that is the place to go! 
