Five years have passed; five summers, with the length Of five long winters! and again I hear These waters, rolling from their mountain-springs With a sweet inland murmur.—Once again
Why it works
These opening lines exemplify blank verse through their consistent iambic pentameter — "five YEARS have PASSED; five SUM-mers, WITH the LENGTH" scans as five clean da-DUM feet — while the absence of any end-rhyme between "length," "hear," "springs," and "again" confirms the defining unrhymed quality that distinguishes the form from the sonnet or heroic couplet.