The relative effects of enhanced and non-enhanced structure input on L2 acquisition of Spanish past tense.

Research on how textual enhancement (TE) affects classroom-based L2 acquisition of grammatical morphemes has shown mixed results. When enhanced conditions were compared with un-enhanced conditions, some studies demonstrated significant effects for textual enhancement, some reported no effect or negative effects and others reported only partial effects for textual enhancement. In contrast, research on how structured input (SI) impacts L2 acquisition of grammatical morphemes has shown consistently beneficial effects. In all studies comparing structured input with other instructional types, SI has brought more beneficial effects or equally beneficial effects. Combining TE and SI, the present study introduces textually enhanced structured input (TESI) as a treatment. The main purpose of this study is to present and examine the differential effects of two types of input-based language instruction on how learners interpret and produce the third-person singular form of the Spanish preterit. This experiment involved 62 participants from first-year Spanish. Sentence-level interpretation and production tests were implemented to assess performance before, immediately following, and fourteen days after treatment. Secondly, the experiment examines whether or not the beneficial affects of structured input are heightened if the features of TE are combined with SI. The results reveal that both instruction types brought about improved performance on the assessment tasks, and the performance of both treatment groups was statistically similar. These results differ from previous research that has compared TE with other types of instruction, where TE at sentence-level task showed better results compared with other types of instruction. (Farley, Peart, & Enns, 2008; Wong, 2002). Although TESI did not prove to be more beneficial than the un-enhanced treatment in the present study, both types of instruction resulted in improvement over time without explicit grammatical information.