Final answer:
In Sonnet 18, the speaker contemplates comparing someone to a summer's day but concludes that the person is more beautiful and constant. Shakespeare uses imagery and metaphor to explore beauty, love, and the passage of time.
Step-by-step explanation:
The line "Shall I compare thee to a summer's day?" is from Sonnet 18 by William Shakespeare. In this sonnet, the speaker is contemplating whether to compare the person they are addressing to a summer's day. The speaker ultimately decides that the person is more beautiful and constant than a summer's day, which can be unpredictable and fleeting. This sonnet is a classic example of Shakespeare's use of imagery and metaphor to explore themes of beauty, love, and the passage of time.