What is an adverb? An adverb tells us how somebody or something DOES something

When writing (painting a picture with words) the picture becomes more clear and more interesting if you can add words to say how something is being done.

For example:

He ate his tea. (The picture is of someone eating his tea)
He ate his tea HUNGRILY. (The picture is now of someone gobbling down his tea because he is HUNGRY!)