Adjuncts and the Processing of Lexical Rules

The standard HPSG analysis of Germanic verb clusters can not explain the observed narrowscope readings of adjuncts in such verb clusters. We present an extension of the HPSG analysis that accounts for the systematic ambiguity of the scope of adjuncts in verb cluster constructions, by treating adjuncts as members of the sul)eat list. The extension uses powerNl reeursive lexical rules, implemented as complex constraints. We show how 'delayed evaluation' teehMques from constrMnt-loglc programming can be used to process such lexical rules. 1 Problem Description 1.1 D u t c h V e r b C l u s t e r s Consider the following Dutch subordinate sentences. (1) dat Arie wil slapen that Arie wants to-sleep (2) dat Arie Bob wil slaan that Arie Bob wants to-hit that Arie wants to hit l/ot) (3) * (lat Arie Bob wil slapen that Arie Bob wants to-sleep that Arie wants to sleep lloh (4) * dat Arie wil Bob slaan (5) dat Arie Bob cadeautjes wil geven that Arie Bob presents want to-give that Arie wants to give presents to Bob (6) * dat Arie Bob wil cadeautjes geven dat Arie wil Bob ca(leautjes geven (7) dat Arie Bob zou moeten kunnen willen knssen that Arie Bob should must can want to-kiss that Arie should be able to want to kiss Ilob The examples 1-3 indicate that in l)utch the arguments of a main verb can be realized to the left of an intervening auxiliary verb, such as a modM verl). Furthermore the sentences in d-6 indicate that in such constructions the arguments must 1)e realized to the left of the auxiliary verbs. In 7 it is illustrated that there can he any numl)er of auxiliaries. 1.2 T h e I I P S G a n a l y s i s o f v e r b c l u s t e r s The now standard analysis within t [PSG of such verb-clusters is based oil ideas from Categorial Grammar (cf. for example Moortgat (1988)) and defined within the HPSG flamework by IIinrichs and Nakazawa (1989). In this analysis auxiliary verbs subcategorize for an unsaturated verb-phrase and for the compleinents that are not yet realized by this verbl)hrase. In other words, the arguments of the embedded verl)-phrase are inherited by the auxiliary. For example, the auxiliary 'wil' might be defined as in Iigure 1. If we assume an ai)plication rule that produces flat vp-structures, then we obtain the derivation in figure 2 for tim infinite verb-phrase (8) . . . Arie boeken wil kunnen geven 1.3 P r o b l e m s w i t h t h e s c o p e o f a d j u n c t s A major problem that this analysis faces is the possibillity of narrow-scope readings ill tile