( ( ( Do not ) ( ( dip ( brush ( in water ) ) ) ( while brushing ) ) ) . )
(ROOT (S (VP (VB Do) (RB not) (VP (VB dip) (NP (NP (NN brush)) (PP (IN in) (NP (NN water)))) (PP (IN while) (S (VP (VBG brushing)))))) (. .)))
Do not dip brush in water while brushing.
(ROOT (S (NP (PRP It)) (VP (MD would) (VP (VB help) (NP (JJ conserve) (NN water)) (S (VP (TO to) (VP (VB turn) (PRT (RP off)) (NP (NN water)) (PP (IN while) (S (VP (VBG brushing) (NP (NNS teeth)))))))))) (. .)))
It would help conserve water to turn off water while brushing teeth.