Am I missing something? This course appears to introduce new words without any prior explanation. What is the point of that? Why would I know what spielt meant when I have never seen the word before? Surely it would be appropriate to introduce the word and then ask the user a question about it. Its not easy to guess either... How many women do you know who "play" regularly?
usually a dotted line under a word will mean, click or hover to see definitions.
also I did notice that i sometomes missed or forgot words from earlier lessons. it has helped to redo or use the strengthen option.
good luck, i hope you returned to keep practicing. this is challenging like a fun game...at least now!