| This dissertation explores development in the expression of unreal conditionals by second language (L2) learners of English. Notions about how things could have been different, might still be different, or differ now from present reality are encompassed by conditional concepts expressed in English in antecedent (IF-clause) and consequent (THEN-clause) constructions (If I had studied harder, I would have passed the exam). Adult learners of a second language come to the language-learning experience with mature cognitive abilities at suspending reality. This dissertation explores the processes by which adult L2 English learners discover the grammar of the expression of unreality in their second language; the process is referred to as acquisitional grammaticalization.; Twelve tutored adult learners of L2 English were observed longitudinally over the period of one year, resulting in an oral corpus of 25,000 predicates. The dissertation analyzes the learners' expressions of conditionality at each interview period. In addition, a detailed analysis of all expressions of modality produced by the learners was conducted. Expressions of modality include modal auxiliaries (can, will), periphrastic modals (have to, want to), and lexical expressions of modality (maybe, think). Finally an SOC analysis was conducted which generated percentages of appropriate use of past tense morphology in past time contexts. This analysis was conducted to determine the likelihood of past tense morphology spreading to expressions of unreality in the learners' oral discourse.; Six stages of development are identified for both the antecedent and consequent. These stages highlight the additive nature of second language acquisition: New forms emerge but do not replace older forms. L2 English learners gradually incorporate productive use of modal auxiliaries and periphrastic modals into their oral discourse overall and specifically in conditional expressions. Few learners show emergent use of target-like expression of conditionality using past tense morphology and modal auxiliaries such as could and would. Results are compared to the formal grammar instruction that learners received and highlight two important notions: (1) Instruction can increase the rate of acquisition, but it does not change the route; and (2) learners acquire only what they are ready to acquire. |
