Can anybody tell me a simple structure of a sonnet ?

There are many forms of sonnet but what I will just cite is about Shakespearean Sonnet:The usual rhyme scheme is end-rhymed a-b-a-b, c-d-c-d, e-f-e-f, g-g. Traditional English Sonnet is on iambic pentameter but not all. The sonnets are almost all constructed from three four-line stanzas (called quatrains) and a final couplet composed in iambic pentameter(a meter used extensively in Shakespeare's plays) (this form is now known as the Shakespearean sonnet).Often, the beginning of the third quatrain marks the volta ("turn"), or the line in which the mood of the poem shifts, and the poet expresses a revelation or epiphany.