The following fluctuate: æt, an, bī (big), bi (be), of, ofer, on, tō, under, þurh, wið, wiðer, ymb. These are generally accented and alliterate, if compounded with substantives or adjectives, but are not accented and do not alliterate if compounded with verbs or other particles,[58] e.g. óferhēah, óferhȳd, but ofercúman, oferbī́dan. The following lines will illustrate this:
(a) prefixes which alliterate:
þāra þe þurh óferhȳ́d úpāstī́geð. Dan. 495.
átol is þīn ónsēon hábbað we éalle swā́. Satan 61.
ýmbe-síttendra ǣ́nig þā́ra. Beow. 2734.
(b) prefixes which do not alliterate:
oððæt he þā býsgu oferbíden hæfde. Gū. 518.
ne wíllað ēow ondrǣ́dan dḗade fḗðan. Exod. 266.
sýmbel ymbsǣ́ton sǣ́grunde nḗah. Beow. 564.[59]
When prepositions precede other prepositions or adverbs in composition, the accent rests on that part of the whole compound which is felt to be the most important. Such compounds fall into three classes: (i) if a preposition or adverb is preceded by the prepositions be, on, tō, þurh, wið, these latter are not accented, since they only slightly modify the sense of the following adverb. Compounds of this kind are: beǣ́ftan, befóran, begéondan, behíndan, beínnan, benéoðan, búfan, bútan, onúfan, onúppan, tōfóran, wiðínnan, wiðū́tan, undernéoðan.[60] Only the second part of the compound is allowed to alliterate in these words: