How does Shakespeare immortalise his friend’s beauty?

Shakespeare’s Sonnet 18 starts with a flattering question to the dear one – “Shall I compare thee to a summer’s day?” But then he himself feels the comparison to be inappropriate. The poet finds his friend’s beauty more charming and lasting than a summer’s day. It is true that the beauty of summer is quite transitory. The new buds of May are shed with a blow of rough wind. The bright light of the sun is dimmed sometimes and every other fair form inevitably decays in the course of time whereas his friend’s beauty is not changeable. His friend achieves, through the romantic verse of the poet, an imperishable loveliness that defies even death. The poet proposes that his friend’s beauty will be celebrated as long as his poem is celebrated among mankind.

Why does the poet think that a comparison between the beloved youth and summer would be inappropriate?

The sonnet “Shall I compare thee to a summer’s day?” begins with a question where the poet ponders if he can compare the beauty of his friend to a summer’s day or not. The poet then finds the comparison to be inappropriate because his friend’s beauty is more impressive and restrained than that of summer. Summer’s beauty is inconstant as the sun is at times too hot while at other times dimmed by the clouds. Even the high summer wind often affects the lovely, new buds that bloom in the month of May. The buds of May are sweet and tender but the strong wind of summer sheds them every now and then. None of the lovely elements of summer lasts forever. But the beauty of the poet’s friend is not subjected to decay. It will always remain ‘untrimmed’ in the lines of the poet’s verse and it will be read as long as men live. So, his beauty, unlike that of summer will live forever.