Because teaching a man to fish will keep him fed for his entire life.
( ( Because teaching ) ( ( ( a man ) ( to fish ) ) ( ( will ( keep ( him ( fed ( for ( his ( entire life ) ) ) ) ) ) ) . ) ) )
(ROOT (S (PP (IN Because) (NP (NN teaching))) (NP (NP (DT a) (NN man)) (PP (TO to) (NP (NN fish)))) (VP (MD will) (VP (VB keep) (S (NP (PRP him)) (VP (VBN fed) (PP (IN for) (NP (PRP$ his) (JJ entire) (NN life))))))) (. .)))
Teaching a man to fish doesn't necessarily mean he will never be hungry.
( ( ( Teaching ( a man ) ) ( to fish ) ) ( ( ( ( does n't ) necessarily ) ( mean ( he ( ( will never ) ( be hungry ) ) ) ) ) . ) )
(ROOT (S (S (VP (VBG Teaching) (NP (DT a) (NN man)) (PP (TO to) (NP (NN fish))))) (VP (VBZ does) (RB n't) (ADVP (RB necessarily)) (VP (VB mean) (SBAR (S (NP (PRP he)) (VP (MD will) (ADVP (RB never)) (VP (VB be) (ADJP (JJ hungry)))))))) (. .)))