Answer:
The sonnet deals with the theme of love but not in the usual way that most other sonnets are written. It rather focus on the bad characteristics of the mistress, comparing her to the other elements to prove his point more clearer.
The volta or the turn is seen after the 12th line.
The poem praises the mistress, contradictory to the previous lines' focus.
The central theme of the whole poem is that of love.
Explanation:
William Shakespeare's Sonnet 130-
The elements that are unusual in this sonnet is the way the whole theme of love is dealt. Mostly, sonnets are made for expressions of love and appreciation of the qualities of the mistress. Ironically, this sonnet instead talks of the bad characters of the mistress and just leaves the last two lines to praise her.
The volta or the turn is seen in the 13th line, where the poem decides to focus on praising the mistress after talking of all the bad qualities first.
The tone of the poem changed in the volta, for it refrains away from the main theme of degrading the mistress and rather focus on praising her in these two lines.
The central theme of the word is to show the love and admiration that the lover has fro his mistress. The theme of love is an overall theme in almost all sonnets,
