The thing started to grow brighter.
( ( The thing ) ( ( started ( to ( grow brighter ) ) ) . ) )
(ROOT (S (NP (DT The) (NN thing)) (VP (VBD started) (S (VP (TO to) (VP (VB grow) (NP (NN brighter)))))) (. .)))
The thing grew dimmer and dimmer by the second.
( ( The thing ) ( ( ( grew ( ( dimmer and ) dimmer ) ) ( by ( the second ) ) ) . ) )
(ROOT (S (NP (DT The) (NN thing)) (VP (VBD grew) (NP (NN dimmer) (CC and) (NN dimmer)) (PP (IN by) (NP (DT the) (NN second)))) (. .)))