SONNET XX

A woman's face with Nature's own hand painted
Hast thou, the master-mistress of my passion;
A woman's gentle heart, but not acquainted
With shifting change, as is false women's fashion;
An eye more bright than theirs, less false in rolling,
Gilding the object whereupon it gazeth;
A man in hue, all hues in his controlling,
Much steals men's eyes and women's souls amazeth.
And for a woman wert thou first created;
Till Nature, as she wrought thee, fell a-doting,
And by addition me of thee defeated,
By adding one thing to my purpose nothing.
But since she prick'd thee out for women's pleasure,
Mine be thy love and thy love's use their treasure.

The sonnet I'm going to analyze is the 20^th and belongs to the shakespearean collection.

Considering the structure, the sonnet follows the traditional shakespearean model it is arranged into three quatrains (with alternated rhyme) and a rhyming couplet. The rhyme scheme is: ABAB CDCD EFEF GG.
The sonnet starts with an image: a woman’s face painted by nature’s hand. The reader can create a mental image of beauty.

In the second line the reader understands that the speaking voice links female beauty to the Fair Youth, defined the “master mistress of my passion” The mistress was the lady who kept the poet's heart. So in the first two lines, the speaker exalts the physical appearance of the Fair Youth and then he adds that he is involved with him.The second part of the first quatrain deepens the comparison between the Fair Youth and women.He has got the same gentle female heart even his love doesn't shift or change as false women's love does.
The second quatrain rests on the semantic field of body, focusing on the face.The forth line expresses the effect of such perfection: the Fair Youth is an irresistible attraction on both men and women (“The Fair Youth amazes women's soul and steals men's eyes”).
The second quatrain better explains the female perfection of the fair Youth. The nouns “man”and “woman” seem to convey a sense of perfect completeness. But the noun “woman” appears more times than “man”.
For that reason, the third quatrain deepens the topic of the genre of the Fair Youth, who seems to be more close to the female genre than to the male one.The speaking voice reveals that at first the fair youth was thought by Nature to be a woman, but Nature itself felt in love with him, and gave him a specific male quality.The reader can understand the message conveyed by Shakespeare is that beauty has no genre: you could be fascinated and attracted independently by a man or by a woman.In the rhyming couplet there should be the solution of the speaking voice's trouble. But there isn't any possible solution, because Nature can't be controlled or changed by humans. Indeed, the first line of the couplet the speaking voice says that Nature gave the Fair Youth as a gift to women's pleasure, and the speaker can't but accept the situation.
In return, last line reveals a partial solution of the speaking voice's trouble: he will have the Fair Youth's love, while women will have pleasure.