nenio

Nenio sits in the correlative table at the crossing of neni- (none) and -o (thing), so it is a thing-word and takes -n as an object: mi vidis nenion. Its row runs neniu (nobody), neniam (never), nenie (nowhere), nenial (for no reason). One negative per clause is the rule: mi vidis nenion, never mi ne vidis nenion. The table is worth learning as a grid rather than as forty separate words.