Shall I compare thee to a summer's day?

Thou art more lovely and more temperate.
Rough winds do shake the darling buds of May,
And summer's lease hath all too short a date.
Sometime too hot the eye of heaven shines,
And often is his gold complexion dimmed,
And every fair from fair sometime declines,
By chance or nature's changing course untrimmed;
But thy eternal summer shall not fade,
Nor lose possession of that fair thou owest;
Nor shall Death brag thou wand'rest in his shade,
When in eternal lines to time thou grow'st:

So long as men can breathe or eyes can see,

So long lives this and this gives life to thee.

The sonnet bears the same title of the first line so it belongs to a collection, in particular to the Shakespearen collection of the 154 sonntes. 

Right from the title the intelligent reader wonders who the speaking voice is speaking to. He only knows that the speaking voice is talking to somebody undefined addressee.

Considering the layout the reader can note the poem is arranged into three quatrains in alternate rhyme and a rhyming couplet. So the rhyme scheme is ABAB CDCD EFEF GG.

In the first quatrain the poet wonders if he shall compare his addressee to a summer’s day. The question may be a rhetorical question because the speaking voice already knows the answer. The answer is in the entirely sonnet. The comparison between the summer’s day and the addressee is unsuitable. Even if the summer’s day is connected to positive qualities, it is not enough to express the great values of the interlocutor. Immediately in the second line the speaking voice explains why the comparison reduces such qualities. As the use of the majoritive comparative, the use of the anaphoric syntax reinforces the idea of the supernal qualities of the “Fair Youth”.

The poet expresses that even nature can sometimes show its negative sides; “May winds sometimes are too rough”. The reader can also hear the repetition of the sound “d” which is a dental sound that compels the reader to stop. In the fourth line the reader gives a further argumentation to explain that his love is better than a summer’s day: the summer is too short. Up to line 2 the speaking voice has mainly exploited the semantic field of nature. All the words refer to the passivity of time. The message the poet wants to convey to his addressee is to get married and get children because in this way he can get the regeneration of his beauty.

In the second quatrain the poet uses a metaphor “the eye of heaven” referring to the sun. The poet continues to explain the semantic field of nature and he magnifies the good qualities of the youth. .The image which the poet wants to convey is that the time passes, therefore every beauty is going to perish: “every fair from fair sometimes decline”.

In the third quatrain, the poet goes on explaining his personal opinion about the Fair Youth. The poet expresses that his Fair Youth has the best characteristics of summer, and these will never go away. With the anaphoric use of language the poet focuses on the beauty of his Fair youth; he will never lose his fair and he will never die.