The poem is a Shakespearean sonnet. Its 14 lines are divided in three quatrains. The idea of the beauty of the “fair youth” has been introduced by a comparison with the charm of a summer’s day in the first quatrain. In Britain, a day in summer is well-known for its dazzling sunshine, beauty and loveliness. The image of the “summer’s day” has been used here to indicate the brightness, beauty and charm of the “fair youth”. To the speaker, his friend first comes as radiant, mirthful and charming as day in summer. But soon he repairs himself saying that his friend is “more lovely and more temperate”.
However, there is a doubt posted in the first line: whether “a summer’s day” is a benefiting comparison to his friend. The suspicion has been logically represented in the following lines. It has been explained through a series contrast. Several images have been used to establish the fact that the qualities of the friend are better than those of the summer’s day.
In the second quatrain, the speaker further argues logically in order to establish that his suspicion is correct. Here the speaker used several images to prove that the qualities of his friend are better than those of summer. The beauty of a day in summer is characteristically uncertain. Because the summer sun suddenly becomes very hot. Sometimes, suddenly it becomes dim due to clouds in the sky. All these imply that the beauty of the friend is not subject to destruction.
In the third quatrain the speaker passes on to the positive qualities of the “fair youth”. The beauty of the “fair youth” will never fade nor will lose it. Death will never be able to defeat him and enjoy proudly its win because the speaker has sheltered him in the immortal lines of this poem.
This is Shakespearean sonnet and bears the traces of Elizabethan period. Shakespeare like other English sonneteers borrowed the Petrarchan sonnet form. The praise of the beauty of the addressee is in tune with the Petrarchan tradition. However, Shakespeare differs from Petrarchan rhyme scheme. Petrarch’s rhyme scheme is abba abba cde cde or cde dcd. But Shakespeare’s rhyme scheme is abab cdcd efef gg. Moreover, Petrarch’s sonnet lines are hendecasyballic (eleven syllabic) while Shakespeare’s lines are ten syllabic.
The words selected by Shakespeare are lucid, and easily managed to fit to the unaccented and accented beats and to the particular rhyme scheme.