... comes alive only when it switches gears to the sentimental . 
(ROOT (S (, ...) (VP (VBZ comes) (ADJP (JJ alive)) (SBAR (WHADVP (RB only) (WRB when)) (S (NP (PRP it)) (VP (VBZ switches) (NP (NNS gears)) (PP (IN to) (NP (DT the) (JJ sentimental))))))) (. .)))
(ROOT (S (, ) (VP (VBZ ) (ADJP (JJ )) (SBAR (WHADVP (RB ) (WRB )) (S (NP (PRP )) (VP (VBZ ) (NP (NNS )) (PP (IN ) (NP (DT ) (JJ ))))))) (. )))