In a Shakespearean Sonnet, the turn typically occurs in the third quatrain, where there is a shift in tone, perspective, or argument. This turn marks the transition from the problem or situation presented in the first two quatrains to the resolution or conclusion in the final quatrain (couplet).
Shakespearean or English sonnets don't have a "turn."
As with many of Shakespeare's sonnets, the turn comes just before the final couplet.
The last two lines of Sonnet 18 by William Shakespeare are indented to create a visual and structural effect known as a "volta" or a turn in the sonnet. This indentation emphasizes the shift in tone or subject matter that often occurs in the concluding couplet of a Shakespearean sonnet.
sonnet
In a sonnet, mood changes are often signaled by shifts in tone, imagery, or diction. These shifts can occur at the volta, or the turn, typically found at the start of the third quatrain in a Shakespearean sonnet or after the octave in a Petrarchan sonnet. The mood change can be used to introduce a new perspective, idea, or emotion that contrasts with or builds upon the preceding content.
Sonnet 18 and sonnet 116
It is also called the English sonnet. The other form is the Italian sonnet, or petrarchan sonnet.
It takes place in line 13 as the speaker becomes defensive about his perception of love.
Sonnet 130
The Sonnet Series - 2013 Sonnet 31 The Old Man and the Sonnet 1-8 was released on: USA: 1 May 2013
The Italian Sonnet
It is a petrarchan sonnet, made out of an octave and a sestet.