SONNET 20

Sonnet 20 explores the boundaries between male and female sexuality and is one of Shakespeare's more radical sonnets. In this crucial, sensual sonnet, the young man becomes the "master-mistress" of the poet's passion.

Right from the analysis of the layout, the reader understands he or she in in front of an Elizabethan model because the sonnet is organised into three quatrains and a rhyming couplet.  Considering conventions of the Shakespearean sonnet, the quatrains should take different aspects of the same problem into consideration.

In the first stanza the poet is addressing to a woman, the reader can understand this from the opening line : ‘A woman’s face, with Nature’s own hand painted’, where Shakespeare is discussing the effeminate beauty of the Fair Youth. The speaker says that the Fair Youth was created by Nature to be like a woman, in lines 3 and 4 he is clearly describing a male who has female qualities, including a gentle heart, but he's not changeable like the false women of the day. So, an intelligent reader understands the speaker is describing the physical characteristics of a male, who has a certain feminine appeal which draws attention from both men and women.

The first six lines support the idea that here we have a man with a woman's face, heart and eyes. The second quatrain, particularly line 7, introduces the reader to the actual man, the so called fair youth.

The next four lines, deal with more fundamental issues like sex and sexuality. In line 9 the speaker states that the youth was first created for a woman. Line 11 has unusual syntax which suits the sense, because the speaker asserts that nature, added something to this woman and that something has to be a penis - male genitalia .So this fair youth, initially intended to be a woman, was made a male because nature changed her mind.  The youth's double sexuality, as portrayed by the poet, accentuates the youth's challenge for the poet. As a man with the beauty of a woman, the youth is designed to be partnered with women but attracts men as well.

In the rhyming couplet, introduced by but .. the speaker says he can only experience platonic love because the fair youth is destined to physically satisfy women. 

What sonnet 20 does highlight is the dual nature of this person's character. He looks like a woman, he's the master mistress of the speaker's passion, he has a gentle heart but is such a man