That would be an interesting day.
( That ( ( would ( be ( an ( interesting day ) ) ) ) . ) )
(ROOT (S (NP (DT That)) (VP (MD would) (VP (VB be) (NP (DT an) (JJ interesting) (NN day)))) (. .)))
It would only be interesting if he turns up.
( It ( ( ( would only ) ( ( be interesting ) ( if ( he ( turns up ) ) ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (MD would) (ADVP (RB only)) (VP (VB be) (ADJP (JJ interesting)) (SBAR (IN if) (S (NP (PRP he)) (VP (VBZ turns) (PRT (RP up))))))) (. .)))