Mandatory alliteration marks fully stressed class I compounds. Class I compounds always alliterate in the second lift in the a-verse; they are excluded from the second lift in the b-verse. Furthermore, they impose an alliterative requirement on a following simplex in the a-verse. Finally, a class I compound whose first two syllables are long and stressed will not be preceded by a stressed monosyllabic simplex.

The alliterative behaviour of the various compounds and compound phrases which have not already been described provides the evidence for their classification as class II or class III compounds.

CLASS II COMPOUNDS

Class II compounds alliterate in the a-verse (except when the stressed element has a prefix which falls in the second weak metrical position (w2)), but they are not excluded from the second lift in the b-verse (where, of course, they do not alliterate), and they impose no alliterative requirement on a following stressed element. They include compounds with fixed stress prefixes, most compounds in which one or both elements have not retained their full semantic value, compound numerals, pronominal and adverbial compounds in æg-, the pronouns nathwylc and welhwylc, simplexes which are preceded by a proclitic and their alliterative equivalents – compound phrases in which one or more of the lift positions is occupied by a verb or an adverb.

The fixed stress prefixes in Beowulf are: æf-, æt-, and- (ond-), ed-, ful-, in-, ofer-, on- (an-), or-, uð-, wiðer- and ymb(e)-.l With the probable exceptions of ofer-, wiðer- and ymb(e)-, these form class II compounds.