1 Let me not to the marriage of true minds

2 Admit impediments. Love is not love

3 Which alters when it alteration finds,

4 Or bends with the remover to remove.

5 Oh no! It is an ever fixed mark

6 That looks on tempests and is never shaken.

7 It is the star to every wandering bark,

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

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

10 Within his bending sickle's compass come.

11 Love alters not with his brief hours and weeks,

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

13 If this be error and upon me proved,

14 I never writ, nor no man ever loved.

Consonance means repeating the same consonant sound at the ends of several words. For instance, in the opening three lines of Sonnet 116, there's an unusually high number of words that end with the sound of the letter t (marked in red).

Euphony means repeating sounds, especially vowel sounds, for a pleasant effect. For instance, the echo of the o sound in the first two lines of this sonnet (marked in green) creates a subtle but pleasing repetition, enhancing a key word in the poem--love.