This type of sonnet was introduced by the Earl of Surry practitioner-William Shakespeare. The stanza of this sonnet falls into three quatrains (1 quatrain = 4 lines) and a concluding couplet (2 lines).
The first quatrain serves as the statement of an idea. The second quatrain is the first development, in which the poet explains the idea presented in the first quatrain. The third quatrains is further developed. The couplet is served as the conclusion of the whole poem. The usual rhyme scheme is ab ab cd cd ef ef gg. However, there may be some other variations of the rhyme scheme.