oh i'll bet they did
( ( oh i ) ( 'll ( bet ( they did ) ) ) )
(ROOT (S (NP (NNP oh) (NNP i)) (VP (MD 'll) (VP (VB bet) (SBAR (S (NP (PRP they)) (VP (VBD did))))))))
I'm bet they did after getting into trouble. 
( I ( ( 'm ( bet ( they ( did ( after ( getting ( into trouble ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBP 'm) (VP (VBN bet) (SBAR (S (NP (PRP they)) (VP (VBD did) (PP (IN after) (S (VP (VBG getting) (PP (IN into) (NP (NN trouble))))))))))) (. .)))