['he', 'explain', 'EmptyParameter', 'EmptyParameter', 'EmptyParameter'] ['what', 'happen', 'EmptyParameter', 'he', 'to']
['<PRP>', 'indicate-78', 'EmptyParameter', 'EmptyParameter', 'EmptyParameter'] ['what', 'occur-48.3', 'EmptyParameter', '<PRP>', 'to']
He can not explain what is happening to him.
<PRP> can not explain what is happening to <PRP>.