we had to endure last summer , 
(ROOT (S (NP (PRP we)) (VP (VBD had) (S (VP (TO to) (VP (VB endure) (NP (JJ last) (NN summer)))))) (, ,)))
(ROOT (S (NP (PRP )) (VP (VBD ) (S (VP (TO ) (VP (VB ) (NP (JJ ) (NN )))))) (, )))