( ( Since ( weight ( is ( ( a measure ) ( of ( ( ( gravity 's ) pull ) ( upon ( an object ) ) ) ) ) ) ) ) ( , ( it ( ( ( would also ) ( be ( appropriate ( to ( say ( that ( ( the elephant ) ( ( weighs more ) ( than ( the feather ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN Since) (S (NP (NN weight)) (VP (VBZ is) (NP (NP (DT a) (NN measure)) (PP (IN of) (NP (NP (NP (NN gravity) (POS 's)) (NN pull)) (PP (IN upon) (NP (DT an) (NN object))))))))) (, ,) (NP (PRP it)) (VP (MD would) (ADVP (RB also)) (VP (VB be) (ADJP (JJ appropriate) (S (VP (TO to) (VP (VB say) (SBAR (IN that) (S (NP (DT the) (NN elephant)) (VP (VBZ weighs) (NP (JJR more)) (PP (IN than) (NP (DT the) (NN feather)))))))))))) (. .)))
Since weight is a measure of gravity's pull upon an object, it would also be appropriate to say that the elephant weighs more than the feather.
(ROOT (S (NP (NNP Weight)) (VP (VBZ is) (NP (NP (DT the) (NN term)) (PP (IN for) (NP (NP (DT the) (NN measure)) (PP (IN of) (NP (NP (DT the) (NN force)) (PP (IN of) (NP (NP (NN gravity)) (VP (VBG pulling) (PRT (RP down)) (PP (IN on) (NP (DT an) (NN object)))))))))))) (. .)))