We really do appreciate your efforts, whatever amount you can contribute.
( We ( really ( ( do ( appreciate ( ( ( your efforts ) , ) ( ( whatever amount ) ( you ( can contribute ) ) ) ) ) ) . ) ) )
(ROOT (S (NP (PRP We)) (ADVP (RB really)) (VP (VBP do) (VP (VB appreciate) (NP (NP (PRP$ your) (NNS efforts)) (, ,) (SBAR (WHNP (WDT whatever) (NN amount)) (S (NP (PRP you)) (VP (MD can) (VP (VB contribute)))))))) (. .)))
Even if you can only give us a little, we are still grateful. 
( ( Even ( if ( you ( ( can only ) ( ( give us ) ( a little ) ) ) ) ) ) ( , ( we ( ( ( are still ) grateful ) . ) ) ) )
(ROOT (S (SBAR (RB Even) (IN if) (S (NP (PRP you)) (VP (MD can) (ADVP (RB only)) (VP (VB give) (NP (PRP us)) (NP (DT a) (JJ little)))))) (, ,) (NP (PRP we)) (VP (VBP are) (ADVP (RB still)) (ADJP (JJ grateful))) (. .)))