( ( ( Grammar Notes ) ( ( The zero ) conditional ) ) ( ( is ( ( ( ( ( a structure ) ( used ( for ( talking ( about ( general truths ) ) ) ) ) ) , ) or ) ( ( ( scientific facts ) -- ) ( things ( which ( always ( happen ( under ( certain conditions ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Grammar) (NNP Notes)) (ADJP (NP (DT The) (NN zero)) (JJ conditional))) (VP (VBZ is) (NP (NP (NP (DT a) (NN structure)) (VP (VBN used) (PP (IN for) (S (VP (VBG talking) (PP (IN about) (NP (JJ general) (NNS truths)))))))) (, ,) (CC or) (NP (NP (JJ scientific) (NNS facts)) (: --) (NP (NP (NNS things)) (SBAR (WHNP (WDT which)) (S (ADVP (RB always)) (VP (VBP happen) (PP (IN under) (NP (JJ certain) (NNS conditions)))))))))) (. .)))
Grammar Notes The zero conditional is a structure used for talking about general truths, or scientific facts -- things which always happen under certain conditions.
(ROOT (S (NP (NP (DT A) (NN statement)) (SBAR (WHNP (WDT that)) (S (VP (VBZ describes) (SBAR (WHNP (WP what)) (S (ADVP (RB always)) (VP (VBZ happens) (PP (IN under) (NP (NP (JJ certain) (NNS conditions)) (PP (IN in) (NP (NN nature)))))))))))) (VP (VBZ is) (ADVP (RB also)) (VP (VBN known) (PP (IN as) (NP (JJ scientific) (NN law))))) (. .)))