Was it a sudden decision on his part, or had he already made up his mind when he parted from me a few hours earlier? 
( ( ( ( ( ( Was it ) ( ( a ( sudden decision ) ) ( on ( his part ) ) ) ) , ) or ) ( ( had he ) ( already ( made ( up ( ( his mind ) ( when ( he ( parted ( ( from me ) ( ( a ( few hours ) ) earlier ) ) ) ) ) ) ) ) ) ) ) ? )
(ROOT (SQ (SQ (VBD Was) (NP (PRP it)) (NP (NP (DT a) (JJ sudden) (NN decision)) (PP (IN on) (NP (PRP$ his) (NN part))))) (, ,) (CC or) (SQ (VBD had) (NP (PRP he)) (VP (ADVP (RB already)) (VBN made) (PP (IN up) (NP (NP (PRP$ his) (NN mind)) (SBAR (WHADVP (WRB when)) (S (NP (PRP he)) (VP (VBD parted) (PP (IN from) (NP (PRP me)) (ADVP (NP (DT a) (JJ few) (NNS hours)) (RBR earlier)))))))))) (. ?)))
Was it something done in the spur of the moment, or was this already a plan for a long time?
( ( ( ( ( ( Was it ) ( something ( done ( in ( ( the spur ) ( of ( the moment ) ) ) ) ) ) ) , ) or ) ( was ( ( this ( ( already a ) plan ) ) ( for ( a ( long time ) ) ) ) ) ) ? )
(ROOT (SQ (SQ (VBD Was) (NP (PRP it)) (NP (NP (NN something)) (VP (VBN done) (PP (IN in) (NP (NP (DT the) (NN spur)) (PP (IN of) (NP (DT the) (NN moment)))))))) (, ,) (CC or) (SQ (VBD was) (NP (NP (DT this) (ADJP (RB already) (DT a)) (NN plan)) (PP (IN for) (NP (DT a) (JJ long) (NN time))))) (. ?)))