There's one thing, he thought to himself, "they can't go on shooting.
( ( There ( 's ( one thing ) ) ) ( , ( he ( ( ( ( ( thought ( to himself ) ) , ) `` ) ( they ( ( ca n't ) ( go ( on shooting ) ) ) ) ) . ) ) ) )
(ROOT (S (S (NP (EX There)) (VP (VBZ 's) (NP (CD one) (NN thing)))) (, ,) (NP (PRP he)) (VP (VBD thought) (PP (TO to) (NP (PRP himself))) (, ,) (`` ``) (S (NP (PRP they)) (VP (MD ca) (RB n't) (VP (VB go) (PP (IN on) (NP (NN shooting))))))) (. .)))
He thought that they could not keep shooting because they were very tired.
( He ( ( thought ( that ( they ( ( could not ) ( keep ( shooting ( because ( they ( were ( very tired ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP He)) (VP (VBD thought) (SBAR (IN that) (S (NP (PRP they)) (VP (MD could) (RB not) (VP (VB keep) (S (VP (VBG shooting) (SBAR (IN because) (S (NP (PRP they)) (VP (VBD were) (ADJP (RB very) (JJ tired)))))))))))) (. .)))