I cannot overemphasize the importance of your support.
( I ( ( ( can not ) ( overemphasize ( ( the importance ) ( of ( your support ) ) ) ) ) . ) )
(ROOT (S (NP (PRP I)) (VP (MD can) (RB not) (VP (VB overemphasize) (NP (NP (DT the) (NN importance)) (PP (IN of) (NP (PRP$ your) (NN support)))))) (. .)))
I believe your support is negligible at best.
( I ( ( believe ( ( your support ) ( is ( negligible ( at best ) ) ) ) ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBP believe) (SBAR (S (NP (PRP$ your) (NN support)) (VP (VBZ is) (ADJP (JJ negligible) (PP (IN at) (ADJP (JJS best)))))))) (. .)))