Simile: a comparison of two things that have at least one thing in common using the words like or as. Example: The flower was as big as the titantic.
Metaphor: is a comparison of two things without using like or as. Example: Emily's eyes are diamonds.
Personification: giving a nonhuman thing a human quality. Example: The alarm clock screamed bloody murder.
Hyperbole: to over exaggerate. Example: Malfoy is so rich he has money flowing from his ears.
Onomatopoeia: sounds. Example: The lighting went CRACK!
Allusion: to give a simile with like or as, but to have a historic event being compared. Example: I was surprised her nose was not growing like Pinocchio's
Idiom: a group of words whose collective meaning is quite different from their individual, literal meaning. Example: Let the cat out of the bag.
Alliteration: to repeat the same sound in the beginning of every word for a distance in a sentence. Example: Sally sued Stewie so he was sad.