A study of near-native sentence processing was carried out using the self-paced reading method. Twenty-three near-native speakers of Spanish were identified on the basis of native-like proficiency, age of onset of acquisition after 15 years, and a minimum of three years ongoing residency in Spanish-speaking countries. The sentence comprehension performance of these non-native participants was compared to that of 35 native monolingual speakers of Mexican Spanish in four self-paced reading experiments testing the processing of subject-object ambiguity, subject-verb number agreement, relative clause attachment, and case markers. In addition to the reading time data that was collected from the self-paced reading study, background data was collected via questionnaire and acceptability judgment data were also collected. The outcomes of the first two experiments indicated that the near-native participant group processes subject-object ambiguity and subject-verb number agreement in a fashion that is largely similar to that of native monolingual speakers of Mexican Spanish. In the third experiment, the relative clause attachment preferences of both participant groups were similar only in the initial stages of processing. Finally, the fourth experiment provided additional evidence of native-like behavior among the near-native group, but also identified an area of difference between the two groups: the processing of case markers in differential object marking. Thus, this dissertation goes against current theories such as the Shallow Structure Hypothesis in providing evidence that adult acquirers can process sentences in a largely native-like manner. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]