Taking out the middle man
If you are learning 2 languages, I HIGHLY recommend choosing the one you know better and making that "your language" to learn the other one. You stop translating and start simply understanding. I am doing this from French to Spanish. I can't wait to go from Spanish to French. Duolingo is fabulous! I am going to Bordeaux in a few weeks and can't wait!!!
This is often named "laddering" on discussion forums: [google:] "site:duolingo.com laddering"
Did you know that you can hear L2 Spanish or French answers if you install Camilo's user script "DuoLingo tree enhancer", even for normal/forward courses?
So with laddering and Duo's mixed translation excercises you will sometimes get right hand side (L2) translations and you can auto-play that French/Spanish audio (on the right translation box after writing the answer) ;)
This even works for multiple-choice and fill in the blank excercises!