while failing to find a spark of its own 
(ROOT (SBAR (IN while) (S (VP (VBG failing) (S (VP (TO to) (VP (VB find) (NP (NP (DT a) (NN spark)) (PP (IN of) (NP (PRP$ its) (JJ own)))))))))))
(ROOT (SBAR (IN ) (S (VP (VBG ) (S (VP (TO ) (VP (VB ) (NP (NP (DT ) (NN )) (PP (IN ) (NP (PRP$ ) (JJ )))))))))))