Then the next day I don't know if you weren't there.
( Then ( ( the ( next ( day I ) ) ) ( ( ( do n't ) ( know ( if ( you ( ( were n't ) there ) ) ) ) ) . ) ) )
(ROOT (S (RB Then) (NP (DT the) (JJ next) (NN day) (NN I)) (VP (VBP do) (RB n't) (VP (VB know) (SBAR (IN if) (S (NP (PRP you)) (VP (VBD were) (RB n't) (ADVP (RB there))))))) (. .)))
On the following day, I didn't know if you weren't there.
( ( On ( the ( following day ) ) ) ( , ( I ( ( ( did n't ) ( know ( if ( you ( ( were n't ) there ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN On) (NP (DT the) (JJ following) (NN day))) (, ,) (NP (PRP I)) (VP (VBD did) (RB n't) (VP (VB know) (SBAR (IN if) (S (NP (PRP you)) (VP (VBD were) (RB n't) (ADVP (RB there))))))) (. .)))