Constituent Ordering in Persian under the Influence of Grammatical Weight: A Processing-based Explanation

In the framework known as processing approach to grammar, it is argued that processing provides a full-fledged functional explanation for all syntactic phenomena including constituent ordering. Linguistic structure is simply built in a way that eases processing difficulty of sentences and results in efficiency of language use. It seems that the operation of that part of the linguistic representation system that leads to formulation of concepts utilizing lexical access procedure is governed by processing mechanisms. The processing mechanisms, as it has put forward by Hawkins (1994) are those that make it possible for humans to recognize (and produce) grammatical structure in a rapid and efficient manner. The formulator is also planned in a way that minimizes the processing load. Therefore, it appears that some ordering regularities and grammatical constraints in word order and syntactic phenomena such as movement are motivated by the flawless performance of this phase of human linguistic processor. According to performance theory and efficiency principles, constituent ordering is influenced by processing efficiency, i.e. the ordering of constituents is intended to facilitate processing. The research aims to study the processing basis of relativisation and syntactic movement known as scrambling and the effects of grammatical weight in Persian by drawing upon evidence from self-paced reading. Adopting an online reading time paradigm, the research was aimed at studying the role of grammatical weight in likelihood of post-verbal movement and processing loads of pairs of corresponding sentences. Hypotheses: Questions increasing the motivation and triggering initiation of doing this research are how different structural configurations of sentences with identical truth condition modify processing level and if the increase of grammatical weight could result in likelihood of syntactic movement. The final questions are how the movement of grammatically heavy constituents including relative clause and scrambled constituents explained in terms of processing implications. Accordingly, four hypotheses were developed in the course of the research. The aforesaid paradigm, as an efficient experimental technique to assess processing speed of syntactic structures, was designed by Open Sesame Software. Two sets of 24 sentences in three levels of weight (light, medium and heavy) and two structural levels (unmarked preverbal constituent and post-verbal one) were presented to 40 randomly selected Persian-speaking participants (between the ages 18 and 40) with university education. The first set consisted of sentences containing relative clause in two configurations and the second set of pairs of scrambled (post-verbal) and unscrambled sentences. Sentences were followed by a yes/no question. Data was analyzed using SPSS and ANOVA test. Findings: In light level, the mean reading time of sentences with canonical constituent ordering was less than those with post-verbal constituents. However, this trend got reversed by the increase of grammatical weight of the constituent subjected to scrutiny. In other word, the post-verbal movement of constituents resulted in reduction of mean reading time in medium-weight sentences. This decline was markedly more significant in heavy sentences. The ordering of constituents and the likelihood of movement is highly weight-sensitive. As a conclusion, the end-weight principle as an incentive to optimize the processing efficiency was approved in Persian.