Poetry uses elements like rhythm, sound, imagery and form to express ideas and emotions. Rhythm gives poetry a musical flow through techniques like meter and beat. Sound is created through devices like rhyme, repetition, alliteration and onomatopoeia. Imagery appeals to the senses using vivid details, figures of speech like similes and metaphors help paint pictures in the reader's mind. There are many forms poetry can take such as couplets, haiku, limericks and free verse.