Adam named all the animals in Genesis 2:
19Now the Lord God had formed out of the ground all the wild animals and all the birds in the sky. He brought them to the man to see what he would name them; and whatever the man called each living creature, that was its name. 20So the man gave names to all the livestock, the birds in the sky and all the wild animals.
God blessed them [Adam and Eve] and said to them, "Be fruitful and increase in number; fill the earth and subdue it. Rule over the fish in the sea and the birds in the sky and over every living creature that moves on the ground."
Man was to rule over the animals.
Barnes explains it this way:
It is the right of the maker, owner, or other superior to give a name; and hence, the receiving of a name indicates the subordination of the thing named to the namer.
The person who did the naming was superior to the objects that were given names.
The act of naming was a big deal in 2 Samuel 12:
26 Meanwhile Joab fought against Rabbah of the Ammonites and captured the royal citadel. 27Joab then sent messengers to David, saying, “I have fought against Rabbah and taken its water supply. 28Now muster the rest of the troops and besiege the city and capture it. Otherwise I will take the city, and it will be named after me.”
Why did God give words for things in Genesis?
Because God and not man who rules over the day, night, sky, land, and seas.