Then I considered.
( Then ( I ( considered . ) ) )
(ROOT (S (RB Then) (NP (PRP I)) (VP (VBD considered)) (. .)))
I refused to even consider it.
( I ( ( refused ( to ( even ( consider it ) ) ) ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBD refused) (S (VP (TO to) (VP (ADVP (RB even)) (VB consider) (NP (PRP it)))))) (. .)))