While the sonnet originated in Italy, William Shakespeare perfected a specific English variation. A Shakespearean sonnet consists of 14 lines written in iambic pentameter, structured into three quatrains (four lines each) and a final rhyming couplet. The rhyme scheme is strictly ABAB CDCD EFEF GG. This structure allows the poet to build an argument or explore a theme through three different lenses before providing a 'turn' or resolution in the final two lines. Shakespeare wrote 154 sonnets, most of which address a 'Fair Youth' or a 'Dark Lady,' revolutionizing the genre by moving away from the idealized, saccharine love poetry of his contemporaries to explore more complex, human emotions.