( ( A gas ) ( ( ( does not ) ( have ( ( ( a ( definite shape ) ) nor ) ( a ( definite size ) ) ) ) ) . ) )
(ROOT (S (NP (DT A) (NN gas)) (VP (VBZ does) (RB not) (VP (VB have) (NP (NP (DT a) (JJ definite) (NN shape)) (CC nor) (NP (DT a) (JJ definite) (NN size))))) (. .)))
A gas does not have a definite shape nor a definite size.
(ROOT (S (NP (NNP Gas)) (VP (VBZ has) (NP (NP (DT no) (JJ definite) (NN volume)) (CC and) (NP (DT no) (JJ definite) (NN shape)))) (. .)))
Gas has no definite volume and no definite shape.