they grow up and you can wait till then 
(ROOT (S (S (NP (PRP they)) (VP (VBP grow) (ADVP (RP up)))) (CC and) (S (NP (PRP you)) (VP (MD can) (VP (VB wait) (PP (IN till) (ADVP (RB then))))))))
(ROOT (S (S (NP (PRP )) (VP (VBP ) (ADVP (RP )))) (CC ) (S (NP (PRP )) (VP (MD ) (VP (VB ) (PP (IN ) (ADVP (RB ))))))))