what was the problem
( what ( was ( the problem ) ) )
(ROOT (SBARQ (WHNP (WP what)) (SQ (VBD was) (NP (DT the) (NN problem)))))
What was the issue?
( What ( ( was ( the issue ) ) ? ) )
(ROOT (SBARQ (WHNP (WP What)) (SQ (VBD was) (NP (DT the) (NN issue))) (. ?)))