While Elizabeth Barrett Browning's "Sonnet 43" from Sonnets from the Portuguese is a Petrarchan, or Italian, sonnet like the others in this collection, it does not follow the traditional pattern of stating a question in the first 8 lines and answering it in the last 6 lines. Instead, Miss Browning poses her question in the first line and answers in all subsequent lines. And, by employing repetition of "I love thee" she emphasizes how deeply she loves Mr. Browning.
In this answering of "How do I love thee?" Mrs. Browning employs metaphors such as
the level of every day's/Most quiet need, by sun and candlelight
This comparison is made with her love as all-encompassing as the even the smallest of need/desire that one may have in the course of a day or night. Interestingly, Mrs. Browning does not use imagery except in this sixth line.
Instead of sensory images, Mrs. Browning uses abstractions to explain her love, also an abstraction. For instance, she uses the abstraction "For the ends of Being and ideal Grace" (l.4) to explain the extent of her love. In other words, her love transcends the mundane beyond the meaning of the world and even to the heavens (ideal Grace)
Browning also makes other metaphoric comparisons: Her love is like the religious fervor that she once felt for the saints (ll11-12) , and her love is as passionate as her "old griefs" (ll 9-10). Her strongest metaphor are in lines 12 and 13:
I love thee with the breath,/Smiles, tears, of all my life!
And, in this break from the rhythm of the poem (iambic pentameter) is the depth of Elizabeth Barrett Browning's emotion.