Franz Schubert, Der Erlkönig

Der Erlkönig was originally a poem written by the famous poet Goethe. The poem describes a story of an Erlking (a mythological supernatural being) who terrorizes a young boy as the boy rides home on horseback with his father. Schubert, a prolific Austrian composer, then used the poem as the basis for this song, which features piano and voice. Throughout almost the entire song, you'll hear a persistent rhythm in the piano which sets the uneasy and tense tone.

I’ve included a performance with vocalist and piano as well as a transcription for piano.

Questions

Pay close attention to the piano's opening passage. Which hand features the melody? When you are playing, how can you ensure that the melody is heard clearly?
Can you guess what language that this song is sung in?
The following is the rhythm that continues through the piano part. What is this rhythm called? (ie. quarter note, half note, whole note, eighth note, triplet, sixteenth note?) If you haven't seen it before, guess!