Last year, they were spooked.
( ( Last year ) ( , ( they ( ( were spooked ) . ) ) ) )
(ROOT (S (NP (JJ Last) (NN year)) (, ,) (NP (PRP they)) (VP (VBD were) (VP (VBN spooked))) (. .)))
They were frightened last year. 
( They ( ( ( were frightened ) ( last year ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBD were) (ADJP (JJ frightened)) (NP (JJ last) (NN year))) (. .)))