One of the characteristic features that distinguish English from other Germanic languages is its near-complete loss of inflection. The inflectional levelling and loss that went on mainly during the Early Middle English period has often been addressed in terms of nouns and articles, whereas adjectival inflection has attracted less attention. This is presumably because studies on adjectives make it necessary to consider not only case, number, and gender (which apply to nouns) but also definiteness and attributive/predicative use as morphosyntactic parameters that determine inflectional forms. This situation makes the problem highly complex. In fact, some believe that adjectival inflections became hardly functional early in the period while others assert that they continued to be functional late in the period.
Research environments for Middle English morphology have changed, however. One indispensable tool that has recently appeared is LAEME (A Linguistic Atlas of Early Middle English) and its text database, developed by Laing and Lass. Despite some relevant parameters (e.g. definiteness) uncoded in the LAEME corpus, its usefulness cannot be denied as it enables us to search for adjectival inflections across scribal texts of different dialects from the critical period.
In the present paper I will take advantage of LAEME to give an overview of the synchronic distribution (across seven dialects) and diachronic development (over four subperiods) of adjectival inflections during Early Middle English. Attempts will also be made to reveal how such parameters as case, number, gender, and definiteness became increasingly irrelevant in the course of the period. Furthermore I will address the question as to how the inflectional levelling of adjectives may be compared to that of nouns.
Laing, Margaret and Roger Lass, comps. A Linguistic Atlas of Early Middle English, 1150-1325. Edinburgh: U of Edinburgh, 2007-. Online. http://www.lel.ed.ac.uk/ihd/laeme1/laeme1.html.