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.
( I ( ( ( do n't ) ( know ( ( how cold ) ( it ( got ( last night ) ) ) ) ) ) . ) )
(ROOT (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))))))) (. .)))