laughs -- sometimes a chuckle , sometimes a guffaw and 
(ROOT (VP (VBZ laughs) (, --) (ADVP (RB sometimes)) (NP (DT a) (NN chuckle)) (, ,) (ADVP (RB sometimes)) (NP (DT a) (NN guffaw)) (CC and)))
(ROOT (VP (VBZ ) (, ) (ADVP (RB )) (NP (DT ) (NN )) (, ) (ADVP (RB )) (NP (DT ) (NN )) (CC )))