( ( Although ( liquids ( ( do not ) ( have ( a ( definite shape ) ) ) ) ) ) ( , ( they ( ( do ( have ( a ( definite volume ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN Although) (S (NP (NNS liquids)) (VP (VBP do) (RB not) (VP (VB have) (NP (DT a) (JJ definite) (NN shape)))))) (, ,) (NP (PRP they)) (VP (VBP do) (VP (VB have) (NP (DT a) (JJ definite) (NN volume)))) (. .)))
Although liquids do not have a definite shape, they do have a definite volume.
(ROOT (S (NP (NN Liquid)) (VP (VBZ has) (NP (NP (DT a) (JJ definite) (NN volume)) (, ,) (CONJP (CC but) (RB not)) (NP (DT a) (JJ definite) (NN shape)))) (. .)))