But there is something you can do to help.
( But ( there ( ( is ( something ( you ( can ( do ( to help ) ) ) ) ) ) . ) ) )
(ROOT (S (CC But) (NP (EX there)) (VP (VBZ is) (NP (NP (NN something)) (SBAR (S (NP (PRP you)) (VP (MD can) (VP (VB do) (S (VP (TO to) (VP (VB help)))))))))) (. .)))
There is nothing you can do to help. 
( There ( ( is ( nothing ( you ( can ( do ( to help ) ) ) ) ) ) . ) )
(ROOT (S (NP (EX There)) (VP (VBZ is) (NP (NP (NN nothing)) (SBAR (S (NP (PRP you)) (VP (MD can) (VP (VB do) (S (VP (TO to) (VP (VB help)))))))))) (. .)))