A metaphor is when you compare two people or things that are dissimilar without using "like" or "as." Ex: Tyler is a dog when it comes to food! (Tyler and the dog are the ones being compared.)
A simile on the other hand DOES use "like" or "as." A simile also compares two dissimilar people or animals. Ex: You are as light as a feather. (The simile I used is "as" and I was comparing you and a feather."
Personification is when you give something a person quality. Ex: The flower hugged the earth as it grew. (Flowers can't hug, only humans can.)
A hyperbole is when you take something and exaggerate it way farther. Ex: I felt like school went on for two million years! (School can't go on for two million years. I was just exaggerating how long school took.)
Alliteration is when you make a sentence with words that all start with the same letter. Ex: Sarah saw Sue sucking on sap. ( The started with the letter "s" so that is what alliteration is.)
An idiom is when a group of words whose collective meaning is quite different from it's literal meaning. Ex: Sarah was a bee when she took the babysitting job. (There where actually no sharks. It just means that Sarah was just really busy.)
Onomatopoeia is when there is sounds. Ex: I heard a loud KABOOM! So I ran downstairs ready to whack a robber in the head with a baseball bat, since I was so scared. (The KABOOM! and whack were just sounds.)
An allusion is when you refer to someone or something famous. Ex: You are as cold as Jack Frost. (The sentence was comparing you and Jack Frost. Jack Frost is famous.)