['he', 'conduct', 'trial', 'EmptyParameter', 'EmptyParameter']
['<PRP>', 'conduct-111.1', "Synset('trouble.n.03')", 'EmptyParameter', 'EmptyParameter']
He was conducting first trials fifteen years ago.
<PRP> was conducting <ORDINAL>0 Synset('trouble.n.03') <DURATION>3 <DATE>4.