This study investigated the acquisition of English tense and aspect through the manipulation of collostructional strength, instructional saliency, and frequency of use in group activities. Past research has focused on some of the factors in this study and their influence on acquisition, such as explicit instruction, but no research to date has attempted to compare the different factors to each other and attempt to create a working model of processing depth with these factors. Additionally, little research exists on the influence proficiency level and personal meaningfulness has on acquisition and in relation to these other determinants, or the role of lexical aspect in verb use and acquisition. The participants in this study were all females from a university in Japan. They were separated into different groups based upon their proficiency level, and each group was given a different treatment of group activities that focused on learning the simple past tense, present perfect, and past progressive over the course of a two week session. Pretests, immediate and delayed posttests were conducted to attempt to measure acquisition. MANCOVAs, Factorial MANCOVAs, and a Chi-Square test were all run to determine the outcome of the treatments. The results of the study suggest a loose continuum in terms of processing depth with explicit instruction as the most effective factor followed by frequency of use, and collostructional strength having minimal and conditional, effectiveness. The results also suggest the powerfulness of proficiency level as a determiner of whether acquisition will occur, with personal meaningfulness playing a lesser but still important role. The lexical aspect use of verbs appeared to show that the learners in this study leaned heavily on activity verbs and using the progressive aspect. Overall the results add to the growing collection of knowledge in understanding how learners develop their verb use as they acquire language. / Applied Linguistics