Researchers studying language comprehension have assumed that, all else being equal, more complex sentence constructions will take longer to process. However, results from experiments, such as the one presented in this paper, which use reading rates as the dependent measure suggest that it is the interaction of specific types of deep structure representations with their surface structure forms that accounts for fluctuations in readers' on-line processing of various sentence types. In particular, those sentences in which the deep structure direct object immediately precedes the verb in the surface structure sequence are easier for comprehenders to process. These data support a dual, parallel processing model of sentence comprehension in which lexical and morphological/relational information are processed independently.