They're both excited about it ...
( They ( ( ( 're both ) ( excited ( about it ) ) ) ... ) )
(ROOT (S (NP (PRP They)) (VP (VBP 're) (DT both) (ADJP (JJ excited) (PP (IN about) (NP (PRP it))))) (: ...)))
They're excited. 
( They ( ( 're excited ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBP 're) (ADJP (JJ excited))) (. .)))