Beowulf was written in Old English, and the dominant feature of the verse is alliteration. Alliteration is the repetition of initial consonants in words placed fairly closely together. In the original Old English, each line in the poem is split up into two parts. Each line has four stressed syllables.  As Seamus Heaney, the translator, explains in his introduction, the first stressed syllable of the second part of the line alliterates with the first or second (or both) stressed syllables of the first part of the line. Because of the way modern English differs from Old English, Heaney's translation cannot follow this scheme exactly, although the pattern can seen for example in line 64: "The fortunes of war favoured Hrothgar." In this line, the first stressed syllable of the second part of the line (the first syllable of "favoured") alliterates with the first stressed syllable of the first part: "fortunes").

Heaney makes plentiful use of alliteration throughout his translation of the poem. The first five lines for example, are consistently alliterative:

So. The Spear-Danes in days gone by and the kings who ruled them had courage and greatness. We have heard of those princes' heroic campaigns.

There was Shield Sheafson, scourge of many tribes, a wrecker of mead-benches, rampaging amongst foes.

The alliterating consonants are underlined. Note that "k" alliterates with a hard "c," since the sounds are the same. The same applies to "w," which is silent when followed by an "r," and "r."

More examples could be chosen at random, such as: The sure-footed fighter felt daunted, the strongest of warriors stumbled and fell. (lines 1543-44)

This is why the poem should ideally be read aloud (as it no doubt was in the days of the mead-hall), because then these poetic effects can be heard.