Jon was fighting at full speed, sweat forming on his brow.
( Jon ( ( was ( fighting ( at ( ( ( full speed ) , ) ( sweat ( forming ( on ( his brow ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Jon)) (VP (VBD was) (VP (VBG fighting) (PP (IN at) (NP (NP (JJ full) (NN speed)) (, ,) (NP (NP (NN sweat)) (VP (VBG forming) (PP (IN on) (NP (PRP$ his) (NN brow))))))))) (. .)))
Jon was fighting demons at full speed.
( Jon ( ( was ( ( fighting demons ) ( at ( full speed ) ) ) ) . ) )
(ROOT (S (NP (NNP Jon)) (VP (VBD was) (VP (VBG fighting) (NP (NNS demons)) (PP (IN at) (NP (JJ full) (NN speed))))) (. .)))