cause parents a few sleepless hours -- 
(ROOT (S (VP (VB cause) (NP (NNS parents)) (NP (DT a) (JJ few) (JJ sleepless) (NNS hours))) (: --)))
(ROOT (S (VP (VB ) (NP (NNS )) (NP (DT ) (JJ ) (JJ ) (NNS ))) (: )))