i'm not sure what the overnight low was
( i ( ( 'm not ) ( sure ( what ( ( the ( overnight low ) ) was ) ) ) ) )
(ROOT (S (NP (FW i)) (VP (VBP 'm) (RB not) (ADJP (JJ sure) (SBAR (WHNP (WP what)) (S (NP (DT the) (JJ overnight) (NN low)) (VP (VBD was))))))))
I don't know how cold it got last night, but it was definitely freezing.
( ( ( ( ( I ( ( do n't ) ( know ( ( how cold ) ( it ( got ( last night ) ) ) ) ) ) ) , ) but ) ( it ( ( was definitely ) freezing ) ) ) . )
(ROOT (S (S (NP (PRP I)) (VP (VBP do) (RB n't) (VP (VB know) (SBAR (WHADJP (WRB how) (JJ cold)) (S (NP (PRP it)) (VP (VBD got) (NP (JJ last) (NN night)))))))) (, ,) (CC but) (S (NP (PRP it)) (VP (VBD was) (ADVP (RB definitely)) (NP (NN freezing)))) (. .)))