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.
( ( The Kal ) ( then ( ( ( nodded ( its head ) ) ( ( up and ) down ) ) . ) ) )
(ROOT (S (NP (DT The) (NNP Kal)) (ADVP (RB then)) (VP (VBD nodded) (NP (PRP$ its) (NN head)) (ADVP (RB up) (CC and) (RB down))) (. .)))