They even smiled at Susan and she smiled back.
( ( ( ( They ( even ( smiled ( at Susan ) ) ) ) and ) ( she ( smiled back ) ) ) . )
(ROOT (S (S (NP (PRP They)) (ADVP (RB even)) (VP (VBD smiled) (PP (IN at) (NP (NNP Susan))))) (CC and) (S (NP (PRP she)) (VP (VBD smiled) (ADVP (RB back)))) (. .)))
They smiled at Susan to warn her of the incoming attackers.
( They ( ( ( smiled ( at Susan ) ) ( to ( ( warn her ) ( of ( the ( incoming attackers ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBD smiled) (PP (IN at) (NP (NNP Susan))) (S (VP (TO to) (VP (VB warn) (NP (PRP her)) (PP (IN of) (NP (DT the) (JJ incoming) (NNS attackers))))))) (. .)))