Sonnet 116 is a Shakespearian sonnet with 14 lines,which includes 3 quatrains and a couplet.The subject of this poem is love and the main theme is that love is ever-lasting.
The first quatrain has a rhyme scheme of ABAC where "minds" rhymes with "finds".The poet uses the rhymes to create a sense of rhythm in the poem.The first line consists of an example of alliteration in the words "me","marriage" and "minds". I think he used the "m" sound to draw our attention to his viewpoint of love as being a type of marriage.Repetition of the words "love","alter" and "remove" shows that the poet was trying to emphasise on the points he made to us.
The second stanza has a rhyme scheme of ABAB where "mark" rhymes with "bark" and "shaken" rhymes with "taken".According to Shakespeare,love would never change. The line "it is an ever-fixed mark" shows this.
I think he probably wanted to convince the reader into agreeing with his opinion.
The third stanza has a rhyme scheme of ABAB,in which the poet used personification "Love's not Time's fool,though rosy lips and cheeks". I think he used this to raise the point that even though beauty fades with time,love does not,and that time has not effect on love.He even capitalises the word "Time" as if it were a person."Bending sickle's compass come" is a nautical imagery used by the poet probably to add to the description of love.
The last stanza of the poem is a couplet with a rhyme scheme of CC.In this stanza,the poet is confident in his opinion of love by suggesting that if he is proved wrong,no one has ever loved.The words "never","nor" and "no" is another example of alliteration.These negative words show the poet's certainty of his opinion of love.
In my opinion,it is a wonderful poem.The use of many literary tools such as metaphors,alliteration and personification etc. and the description of love by what it is and is not makes the poem one of the most famous and significant ones written by Shakespeare.