( and ( ( begin ( growing again ) ) . ) )
(ROOT (S (CC and) (VP (VB begin) (VP (VBG growing) (ADVP (RB again)))) (. .)))
and begin growing again.
(ROOT (S (NP (NP (DT An) (NN acorn)) (VP (VBG growing) (PP (IN into) (NP (DT an) (JJ adult) (NN tree))))) (VP (MD will) (VP (VB take) (NP (DT the) (JJS longest) (NN time)) (S (VP (TO to) (VP (VB observe)))))) (. .)))