But the conflict did not begin on 9/11.
( But ( ( the conflict ) ( ( ( did not ) ( begin ( on 9/11 ) ) ) . ) ) )
(ROOT (S (CC But) (NP (DT the) (NN conflict)) (VP (VBD did) (RB not) (VP (VB begin) (PP (IN on) (NP (CD 9/11))))) (. .)))
9/11 was the first sign of conflict.
( 9/11 ( ( was ( ( the ( first sign ) ) ( of conflict ) ) ) . ) )
(ROOT (S (NP (CD 9/11)) (VP (VBD was) (NP (NP (DT the) (JJ first) (NN sign)) (PP (IN of) (NP (NN conflict))))) (. .)))