Then he shrugged.
( Then ( he ( shrugged . ) ) )
(ROOT (S (RB Then) (NP (PRP he)) (VP (VBD shrugged)) (. .)))
He wasn't sure what to say.
( He ( ( ( was n't ) ( sure ( what ( to say ) ) ) ) . ) )
(ROOT (S (NP (PRP He)) (VP (VBD was) (RB n't) (ADJP (JJ sure) (SBAR (WHNP (WP what)) (S (VP (TO to) (VP (VB say))))))) (. .)))