Each line is made up of two half-lines (in Old English studies usually called verses) of contrasting rhythms separated by a brief pause.

Each half-line consists of two rhythm units (feet).

Each foot contains a stressed syllable, shown here underlined, preceded or followed by one or more unaccented syllables.

The two halves are joined by the repetition of the initial sound of certain accented syllables (alliteration). One such syllable in each half-line must alliterate. In the second half-line, the first accented syllable is the dominant one, and this may alliterate with either or both the accented syllables in the first half-line.

The rules governing alliteration are simple: a pair of accented syllables alliterate when they both begin with the same consonant, or when they both begin with a vowel. Any vowel can alliterate with any other vowel.