Answer:
He has one and a person has two. A citizen has three. And a human being has four. A personality has five. And an inhabitant of earth has six.
Two brothers we are, great burdens we bear. All day we are bitterly pressed. Yet this I will say, we are full all the day, and empty when go to rest.
What has 4 legs in the morning, 2 legs in the evening and 3 legs in the night?
Inside a burning house, this thing is best to make. And best to make it quickly, before the fire's too much to take.
Tall in the morning, short at noon, gone at night. But I'll be back soon.
All about, but cannot be seen, Can be captured, cannot be held, No throat, but can be heard. Who am I?