to whom we might not give a second look if we passed them on the street 
(ROOT (SBAR (WHPP (IN to) (WHNP (WP whom))) (S (NP (PRP we)) (VP (MD might) (RB not) (VP (VB give) (NP (DT a) (JJ second) (NN look)) (SBAR (IN if) (S (NP (PRP we)) (VP (VBD passed) (NP (PRP them)) (PP (IN on) (NP (DT the) (NN street)))))))))))
(ROOT (SBAR (WHPP (IN ) (WHNP (WP ))) (S (NP (PRP )) (VP (MD ) (RB ) (VP (VB ) (NP (DT ) (JJ ) (NN )) (SBAR (IN ) (S (NP (PRP )) (VP (VBD ) (NP (PRP )) (PP (IN ) (NP (DT ) (NN )))))))))))