they don't allow they don't do that
( they ( ( do n't ) ( allow ( they ( ( do n't ) ( do that ) ) ) ) ) )
(ROOT (S (NP (PRP they)) (VP (VBP do) (RB n't) (VP (VB allow) (SBAR (S (NP (PRP they)) (VP (VBP do) (RB n't) (VP (VB do) (NP (DT that))))))))))
Yes, it's allowed and they do it often.
( ( ( ( Yes ( , ( it ( 's allowed ) ) ) ) and ) ( they ( ( do it ) often ) ) ) . )
(ROOT (S (S (INTJ (UH Yes)) (, ,) (NP (PRP it)) (VP (VBZ 's) (VP (VBN allowed)))) (CC and) (S (NP (PRP they)) (VP (VBP do) (NP (PRP it)) (ADVP (RB often)))) (. .)))