But while the prepositional prefix thus does not carry the alliteration owing to its want of accent, some of the adverbs used in composition are accented, others are unaccented, and others again may be treated either way. When the adverbial prefix originally stood by itself side by side with the verb, and may in certain cases still be disjoined from it, it has then the primary accent, because it is felt as a modifying element of the compound. When, however, the prefix and the verb have become so intimately united as to express one single notion, the verb takes the accent and the prefix is treated as proclitic, and there is a third class of these compounds which are used indifferently with accent on the prefix or on the verb.
Some of the commonest prefixes used in alliteration are[57]: and, æfter, eft, ed, fore, forð, from, hider, in, hin, mid, mis, niðer, ongēan, or, up, ūt, efne, as in compounds like ándswarian, íngong, ǽfterweard, &c.:
on ándswáre and on élne stróng. Gū. 264.
ǽðelīc íngong éal wæs gebúnden. Cri. 308.
and ḗac þāra ýfela órsorh wúnað. Met. vii. 43.
ú plang gestṓd wið Ísrahḗlum.Ex. 303.
Prefixes which do not take the alliteration are: ā, ge, for, geond, oð, e.g.
āhōn and āhébban on hḗahne bḗam. Jul. 228.
hǽfde þā gefóhten fóremǣrne blǣ́d. Jud. 122.
brónde forbǽrnan ne on bǣ́l hládan. Beow. 2126.