Julius nodded gravely.
( Julius ( ( nodded gravely ) . ) )
(ROOT (S (NP (NNP Julius)) (VP (VBD nodded) (ADVP (RB gravely))) (. .)))
Julius nodded solemnly after hearing sad news. 
( Julius ( ( ( nodded solemnly ) ( after ( hearing ( sad news ) ) ) ) . ) )
(ROOT (S (NP (NNP Julius)) (VP (VBD nodded) (ADVP (RB solemnly)) (PP (IN after) (S (VP (VBG hearing) (NP (JJ sad) (NN news)))))) (. .)))