The controller checked to see if American Airlines could establish communication with American 11.
( ( The controller ) ( ( checked ( to ( see ( if ( ( American Airlines ) ( could ( ( establish communication ) ( with ( American 11 ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN controller)) (VP (VBD checked) (S (VP (TO to) (VP (VB see) (SBAR (IN if) (S (NP (NNP American) (NNPS Airlines)) (VP (MD could) (VP (VB establish) (NP (NN communication)) (PP (IN with) (NP (NNP American) (CD 11))))))))))) (. .)))
The controller gave up trying to find a signal and declared American 11 a lost cause.
( ( The controller ) ( ( ( ( ( ( gave up ) ( trying ( to ( find ( a signal ) ) ) ) ) and ) ( declared ( American 11 ) ) ) ( a ( lost cause ) ) ) . ) )
(ROOT (S (NP (DT The) (NN controller)) (VP (VP (VBD gave) (PRT (RP up)) (S (VP (VBG trying) (S (VP (TO to) (VP (VB find) (NP (DT a) (NN signal)))))))) (CC and) (VP (VBD declared) (NP (NNP American) (CD 11))) (NP (DT a) (JJ lost) (NN cause))) (. .)))