['they', 'know', 'EmptyParameter', 'EmptyParameter', 'EmptyParameter'] ['they', 'do', 'EmptyParameter', 'EmptyParameter', 'EmptyParameter']
['<PRP>', 'comprehend-87.2', 'EmptyParameter', 'EmptyParameter', 'EmptyParameter'] ['<PRP>', 'act-114-1', 'EmptyParameter', 'EmptyParameter', 'EmptyParameter']
They both know, until they do.
<PRP> both know, until <PRP> do.