Porches and stoops, those symbols of a vibrant social life, stopped being used as gathering places for a rather practical reason--air conditioning.
( ( ( ( ( ( Porches and ) stoops ) , ) ( ( those symbols ) ( of ( a ( vibrant ( social life ) ) ) ) ) ) , ) ( ( stopped ( being ( used ( as ( ( gathering places ) ( for ( ( ( a ( ( rather practical ) reason ) ) -- ) ( air conditioning ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNS Porches) (CC and) (NNS stoops)) (, ,) (NP (NP (DT those) (NNS symbols)) (PP (IN of) (NP (DT a) (JJ vibrant) (JJ social) (NN life)))) (, ,)) (VP (VBD stopped) (S (VP (VBG being) (VP (VBN used) (PP (IN as) (S (VP (VBG gathering) (NP (NNS places)) (PP (IN for) (NP (NP (DT a) (ADJP (RB rather) (JJ practical)) (NN reason)) (: --) (NP (NN air) (NN conditioning))))))))))) (. .)))
Air conditioning is the primary reason for the demise of outdoor gathering.
( ( Air conditioning ) ( ( is ( ( the ( primary reason ) ) ( for ( ( the demise ) ( of ( outdoor gathering ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Air) (NNP conditioning)) (VP (VBZ is) (NP (NP (DT the) (JJ primary) (NN reason)) (PP (IN for) (NP (NP (DT the) (NN demise)) (PP (IN of) (NP (JJ outdoor) (NN gathering))))))) (. .)))