Um, not really anything unusual.
( ( ( Um , ) ( ( not really ) ( anything unusual ) ) ) . )
(ROOT (NP (NP (NNP Um)) (, ,) (NP (NP (RB not) (RB really)) (ADJP (NN anything) (JJ unusual))) (. .)))
It's happened before.
( It ( ( 's ( happened before ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ 's) (VP (VBN happened) (ADVP (RB before)))) (. .)))