How do I love thee? Let me count the ways!
I love thee to the depth and breadth and height
My soul can reach, when feeling out of sight
For the ends of Being and Ideal Grace.
I love thee to the level of every day's
Most quiet need, by sun and candle-light.
I love thee freely, as men strive for Right.
I love thee purely, as they turn from Praise.
I love thee with the passion put to use
In my old griefs, and with my childhood's faith.
Her love is both freely chosen (not arranged or imposed by practical necessity) and well chosen (as when we make the “right” moral choice). This is the person she  wants  to be with and  should  be with. 
 
 It is interesting to note that Elizabeth had progressive views on equality; as a man can love, a women can also love. As a man could claim/posses a woman, a woman should also be able to earn her right to claim a man as her own. Love should be reciprocated, and for this reason a right that is free. 
 The phrase ‘I love thee freely’ is echoed in the following line with another adverb, ‘I love thee purely’, and in the line after with an  adverbial clause  ‘I love thee with the passion put to use …’ . This has a rhythmic, hypnotic effect as well as increasing emphasis, as if she is being overwhelmed by her feelings, as she composes. The similarity of structure of these lines is known as  syntactic parallelism .