Sonnet 18 Summary
The speaker begins by asking whether he should or will compare "thee" to a summer day. He says that his beloved is more lovely and more even-tempered. He then runs off a list of reasons why summer isn’t all that great: winds shake the buds that emerged in Spring, summer ends too quickly, and the sun can get too hot or be obscured by clouds.
He goes on, saying that everything beautiful eventually fades by chance or by nature’s inevitable changes. Coming back to the beloved, though, he argues that his or her summer (or happy, beautiful years) won’t go away, nor will his or her beauty fade away. Moreover, death will never be able to take the beloved, since the beloved exists in eternal lines (meaning poetry). The speaker concludes that as long as humans exist and can see (so as to read), the poem he’s writing will live on, allowing the beloved to keep living as well.