The main clause of Sonnet 29 begins the turn. Where is it? How does the speaker’s tone, or attitude, change after the turn?

The simile of a lark is developed in lines 10-12, when the speaker describes the effect that a thought of his love has on his "state," or emotional well-being. The fact that the lark rises from the "sullen earth" at "break of day" implies that the day is much happier than the night; day break is compared to the dawning of a thought of the beloved. As the lark "sings hymns at heaven's gate," so the poet's soul is invigorated with the thought of the fair lord, and seems to sing to the sky with rejuvenated hope.