Credit to Ali from Facebook for these: English Terms Question Answers | Facebook
Metaphor: To say something is something else that is commonly known to create more meaning. eg. You're a pig.
Simile: To compare something with something similar to create more meaning, using like or as. eg. He ate like a pig. The boy was as fat as a pig.
Alliteration: To repeat a letter at the beginning of several words in succession. eg. The dumb dog died (d is repeated). The big bad bear (b repeated)
Assonance: The repetition of sounds (vowels) in successive words in a sentence to create sound imagery. Used often in poems eg. Floating down, the sound resounds around the icy waters underground — Pink Floyd , on a proud round cloud in white high night.
Hyperbole: Over exaggeration used for emphasis. eg. I have told you a million times.
Cliche: A phrase so often used that has lost its meaning or effect. eg. it's raining cats and dogs
Onomatopoeia: words than sound like what they read. Used often in poems to create sound imagery. eg. oink, roar, meow.
Personification: Giving living characteristics to non-living things. eg. The cloud cried. The wind roared.
Pun: a play on words that have more than one meaning. eg. Two silk worms had a race. They ended up in a tie.
Oxymoron: Words which contradict eachother and are used for emphasis and giving more effect. eg. deafening silence.