To compare the poetic elements in "Sonnet 18" and "Sonnet 43" by William Shakespeare, the two correct statements are:
- Both consist of a single stanza of fourteen lines.
- Both are sonnets that use the same rhyme scheme.
Both poems are indeed sonnets, characterized by their structure of fourteen lines, and they follow the typical rhyme scheme associated with Shakespearean sonnets (ABABCDCDEFEFGG). The other options regarding similes and personification, rhyming couplets, and iambic pentameter contain inaccuracies or do not hold true for both poems. For example, "Sonnet 43" does not conclude with a rhyming couplet, and they do not contain five syllables per line but rather ten syllables in an iambic meter.