Romeo and Juliet belongs to a tradition of tragic romances stretching back to antiquity. Its plot is based on an Italian tale, translated into verse as The Tragical History of Romeus and Juliet by Arthur Brooke in 1562, and retold in prose in Palace of Pleasure by William Painter in 1582. Shakespeare borrowed heavily from both but, to expand the plot, developed supporting characters, particularly Mercutio and Paris. Believed written between 1591 and 1595, the play was first published in a quarto version in 1597. This text was of poor quality, and later editions corrected it, bringing it more in line with Shakespeare's original. Shakespeare's use of dramatic structure, especially effects such as switching between comedy and tragedy to heighten tension, his expansion of minor characters, and his use of sub-plots to embellish the story, has been praised as an early sign of his dramatic skill. The play ascribes different poetic forms to different characters, sometimes changing the form as the character develops. Romeo, for example, grows more adept at the sonnet over the course of the play.