Few Americans had noticed it.
( ( Few Americans ) ( ( had ( noticed it ) ) . ) )
(ROOT (S (NP (JJ Few) (NNPS Americans)) (VP (VBD had) (VP (VBN noticed) (NP (PRP it)))) (. .)))
Americans are not very observant.  
( Americans ( ( ( are not ) ( very observant ) ) . ) )
(ROOT (S (NP (NNPS Americans)) (VP (VBP are) (RB not) (ADJP (RB very) (JJ observant))) (. .)))