The mechanism of displacement plays an important part in the metrical grammar of the Beowulf-poet. When a sentence particle is displaced from its normal unstressed position in the first dip of the clause, it will be marked by alliteration or it will take metrical stress or both.

Displacement is spoken of as though it referred to a procedure whereby the poet would remove a word from its normal syntactical position and insert it somewhere else in the verse clause. But this assumption will not adequately account for all the observed phenomena. Furthermore, it is rooted in a prior assumption – that Old English poetry was essentially, not just secondarily or superficially, the product of a literate culture. We can readily imagine a poet, pen in hand, mentally shifting a word from its expected position in one verse and fitting it into some other verse, possibly several lines removed, while making the necessary adjustments in both verses in order to preserve their proper rhythms. But to suppose that an oral poet, employing the traditional half-line formulae, could or would engage in such mental gymnastics in the midst of an extemporaneous performance seems intuitively unlikely. Even if, as I assume, the Beowulf-poet and others like him in the monastic culture of Anglo-Saxon England wrote down their poems by a process of self-dictation, their steady reliance on the traditional formulae and formulaic systems implies that they continued to practise the techniques of oral composition.