I'm sonnet 116 by william shakespear what text structure of a sonnet do these lines illustrate?

This question is incomplete. The complete question would be:

From Sonnet 116, by William Shakespeare

Love's not Time's fool, though rosy lips and cheeks

Within his bending sickle's compass come;

Love alters not with his brief hours and weeks,

But bears it out even to the edge of doom.

What text structure of a sonnet do these lines from Sonnet 116 illustrate?

The answer is a quatrain.

Explanation:

A sonnet has very specific characteristics. In the case of the English sonnet, on of these characteristics is its structure. It is comprised of four stanzas, more specifically three quatrains (four lines) and a couplet (two lines). The rhyme scheme is usually ABAB CDCD EFEF GG.

The lines we are analyzing here constitute the third quatrain of Sonnet 116 by Shakespeare. The rhyme scheme is represented by the capitals letters at the end of each line.

Let me not to the marriage of true minds  A

Admit impediments. Love is not love  B

Which alters when it alteration finds,  A

Or bends with the remover to remove.  B

O no! it is an ever-fixed mark  C

That looks on tempests and is never shaken;  D

It is the star to every wand'ring bark,  C

Whose worth's unknown, although his height be taken.  D

Love's not Time's fool, though rosy lips and cheeks  E

Within his bending sickle's compass come;  F

Love alters not with his brief hours and weeks,  E

But bears it out even to the edge of doom.  F

If this be error and upon me prov'd,  G

I never writ, nor no man ever lov'd.  G