( He ( ( may ( ( have even ) ( ( poured ( motor oil ) ) ( down ( the ( storm drain ) ) ) ) ) ) ... ) )
(ROOT (S (NP (PRP He)) (VP (MD may) (VP (VB have) (ADVP (RB even)) (VP (VBN poured) (NP (NN motor) (NN oil)) (PP (IN down) (NP (DT the) (NN storm) (NN drain)))))) (: ...)))
He may have even poured motor oil down the storm drain...
(ROOT (S (NP (NNP Motor) (NN oil)) (VP (VBZ is) (NP (NP (DT a) (JJ harmful) (NN substance)) (SBAR (WHNP (WDT that)) (S (VP (MD must) (RB not) (VP (VB be) (VP (VBN drained) (PP (IN into) (NP (DT a) (NN storm) (NN sewer)))))))))) (. .)))