Beowulf follows the structured form that most Anglo-Saxon works did up until the 10th century. The verse is unrhymed, without stanzas, and the lines have definite end-stops, which we don't use in modern poetry. For example, the number of unstressed syllables are irregular and unequal, but are actually combined with the stressed ones into what they called 'feet' in accordance to certain rules of form. The use of one or more stressed syllables in each half line has to be in alliteratio with one in the other half-line.
