['he', 'care', 'EmptyParameter', 'he', 'about']
['<PRP>', 'care-88.1-1', 'EmptyParameter', '<PRP>', 'about']
For some reason unknown to him, he cares about him.
for some Synset('information.n.02') Synset('unknown.a.01') to him, <PRP> cares about <PRP>.