Please give a complete summary of Shakespeare's Sonnet 18.

In Shakespeare's Sonnet 18, the speaker asks permission or
suggests that he will compare his beloved to a summer's
day.

Shall I compare thee to a summer's
day?

Thou art more lovely and
more temperate:

Actually, the beloved
is more lovely and more constant than a summer day. Still, the writer captures the
beauty of his beloved in a comparison of her beauty and a warm day in summer. Of course,
he mentions that a summer day is often too short, but he claims that his beloved's youth
shall not fade.

Although summer can be too hot or too
short, in this poem, the beloved is perfect. To compare her to a summer's day gives an
idea of her beauty, but in reality, she is far more beautiful than a summer day. For his
beloved will not fade or lose her beauty, but a summer day will end. Not even death can
claim his beloved. She becomes immortal in the words of this
poem.

Truly, his beloved has become immortal. That is the
difference in a summer day and his beloved. A summer day will end, but his beloved will
forever live on in the sweet verse of this
poem:

But thy eternal summer shall not
fade, Nor lose possession of that fair thou ow'st, Nor shall death brag thou wander'st
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.