( What ( ( are ( corals ( and ( coral reefs ) ) ) ) ? ) )
(ROOT (SBARQ (WHNP (WP What)) (SQ (VBP are) (NP (NN corals) (CC and) (NN coral) (NNS reefs))) (. ?)))
What are corals and coral reefs?
(ROOT (S (NP (NNS Corals)) (VP (VBP build) (NP (NP (JJ hard) (NNS exoskeletons)) (SBAR (WHNP (WDT that)) (S (VP (VBP grow) (S (VP (TO to) (VP (VB become) (NP (NN coral) (NNS reefs)))))))))) (. .)))