Inflectional morphology and compounding in English : a single route, associative memory based account
Native English speakers include irregular plurals in English compounds (e. g., mice chaser) more frequently than regular plurals (e. g., *rats chaser) (Gordon, 1985). This dissociation in inflectional morphology has been argued to stem from an internal and innate morphological constraint as it is thought that the input to which English speaking children are exposed is insufficient to signal that regular plurals are prohibited in compounds but irregulars might be allowed (Marcus, Brinkmann, Clahsen, Weise & Pinker, 1995). In addition, this dissociation in English compounds has been invoked to support the idea that regular and irregular morphology are mediated by separate cognitive systems (Pinker, 1999). It is argued in this thesis however, that the constraint on English compounds can be derived from the general frequencies and patterns in which the two types of plural (regular and irregular) and the possessive morpheme occur in the input. In English both plurality (on regular nouns) and possession are denoted by a [-s] morpheme. It is argued that the constraint on the use of plurals in English compounds occurs because of competition between these two identical morphemes. Regular plurals are excluded before a second noun because the pattern -noun-[-sJ morpheme- noun- is reserved for marking possession in English. Irregular plurals do not end in the [-s] morpheme and as such do not compete with the possessive marker and consequently may be optionally included in compounds. Interestingly, plurals are allowed in compounds in other languages where this competitive relationship does not exist (e. g. Dutch (Schreuder, Neijt, van der Weide & Baayen, 1998) and French (Murphy, 2000). As well as not being in competition with the possessive structure irregular plurals also occur relatively infrequently in the input compared to regular plurals. This imbalance between the frequency of regular and irregular plurals in compounds also affects the way the two types of plural are treated in compounds. Thus there is no need for an innate mechanism to explain the treatment of plurals in English compounds. There is enough evidence available in the input to constrain the formation of compound words in English.