The Kal nodded.
( ( The Kal ) ( nodded . ) )
(ROOT (S (NP (DT The) (NNP Kal)) (VP (VBD nodded)) (. .)))
The Kal then nodded its head up and down to signal that it wanted to fight.
( ( The Kal ) ( ( then ( ( ( nodded ( its head ) ) ( ( up and ) down ) ) ( to ( signal ( that ( it ( wanted ( to fight ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNP Kal)) (VP (ADVP (RB then)) (VBD nodded) (NP (PRP$ its) (NN head)) (PRT (RP up) (CC and) (RP down)) (S (VP (TO to) (VP (VB signal) (SBAR (IN that) (S (NP (PRP it)) (VP (VBD wanted) (S (VP (TO to) (VP (VB fight))))))))))) (. .)))