( ( A gas ) ( ( is ( ( ( a phase ) ( of matter ) ) ( that ( has ( ( ( no ( definite volume ) ) or ) shape ) ) ) ) ) . ) )
(ROOT (S (NP (DT A) (NN gas)) (VP (VBZ is) (NP (NP (DT a) (NN phase)) (PP (IN of) (NP (NN matter))) (SBAR (WHNP (WDT that)) (S (VP (VBZ has) (NP (NP (DT no) (JJ definite) (NN volume)) (CC or) (NP (NN shape)))))))) (. .)))
A gas is a phase of matter that has no definite volume or shape.
(ROOT (S (NP (NP (DT The) (NN gas) (NN form)) (PP (IN of) (NP (NN matter)))) (VP (VBZ has) (NP (NP (ADVP (DT neither)) (DT a) (JJ definite) (NN shape)) (CC nor) (NP (DT a) (JJ definite) (NN volume)))) (. .)))