Die -ar-Plurale im Altwestfriesischen: mit einem Exkurs über die sächlichen Plurale im Westfriesischen

Most East- and North Frisian dialects and all the Old East Frisian sources attest to the Old Frisian ending -ar in the nom./acc.pl. of the masculine a-stems. For Old West Frisian, current grammars of Old Frisian mention only the existence of the ending -an in this paradigm form, which may have replaced the older -ar ending before the first attestations. The archaic Old West Frisian texts in Codex Unia reveal seven instances of -ar as a nom./acc.pl. ending of masculine nouns. These instances attest to the earlier existence of -ar also in Old West Frisian.
An additional indication that in pre-attested Old West Frisian the plural ending -ar was categorically replaced by -an comes from the historical s-stem words klath ‘cloth’ and kind ‘child’, which also show up with -an in Old West Frisian, against -ar in Old East Frisian. In an excursus into Middle and Early Modern West Frisian it is shown that the contrast between uninflected plurals for historical a-stem neuter nouns and -an in the s-stem nouns left its traces until ca. 1700.