The Beowulf poet had to maintain the sense of a two-word verse norm while employing extrametrical words before the foot and word groups within the foot. This task was particularly challenging because verse patterns were so numerous and because they occurred at unpredictable intervals. With no advance knowledge of the poet's metrical intentions, the audience had to recover the underlying two-word pattern in each case from the linguistic material of the verse. Old English poets were willing to limit the frequency of complex variants, and they did exclude some verse patterns from the metrical system altogether (e.g. Sxs/S, Ssx/Sx, Sxx/S). Such constraints were imposed only when there was a serious threat to metrical coherence, however. The poets seem to have exploited every viable two-word pattern available to them.

Linguistic developments could affect the way in which metrical variety was reconciled with a clear two-foot structure. If changes in Old Norse made a given pattern more difficult to recover from linguistic material, we would expect that pattern to be used less often or eliminated. If linguistic obstacles to scansion of a given pattern disappeared from Old Norse, on the other hand, we would expect that pattern to be exploited for metrical variety. Old Norse poets did employ verse patterns not found in Beowulf, and they did minimize or abandon use of certain patterns attested in Old English poems. Within the word-foot framework, these differences between the two traditions can be seen as shrewd artistic responses to divergent linguistic histories.