Research in second language acquisition confirms that the linguistic features learners are most likely to have long-term difficulty acquiring are those in which there is a misleading similarity between the L1 and the L2. This difficulty may be particularly great in classrooms where learners share the same L1, resulting in successful communication even when students are making errors on features influenced by their L1. Previous research shows that form-focused instruction can help learners make progress toward correct use of these features. We have hypothesized that it may be necessary to provide instruction that is not only explicit with regard to the L2, but that also draws attention to the specific differences between L1 and L2 (Spada & Lightbown 1999). Participants in this study were approximately 90 French-speaking students (11-12 years old) in four intact classes. They were in the second half of a five-month communicative intensive ESL course. Two classes received instruction on the possessive determiners his and her, and two others received instruction on question formation (with a focus on inversion with noun subjects). The instruction included information directing the students' attention to the contrasts between their L1, French, and their L2, English. Over four weeks, students engaged in a variety of activities that gave them opportunities to hear and produce the target features. They were given a "rule of thumb" for either possessive determiners or question inversion. Throughout the instructional period, they were reminded of the rule of thumb and given corrective feedback by their teachers when they made errors on the feature that was in focus in their class. The question classes and possessive determiner classes served as uninstructed comparison groups for each other. Pretests and posttests consisted of oral production and paper and pencil tasks. Following the completion of the posttests, students were interviewed to explore their metalinguistic awareness of possessive determiners. The classes that received instruction on possessive determiners outperformed the comparison classes on tasks assessing their knowledge of this feature. The interview data showed evidence of learning in the instructed group, even among students whose performance on the oral production and paper and pencil tasks did not suggest much improvement. The classes that received instruction on questions also improved on the feature they were taught, but the changes were less substantial and, on most measures, not greater than those in the uninstructed group. One explanation for the findings is related to differences between the linguistic features under investigation. A misused or misunderstood possessive determiner is more likely to cause communication problems than a question without inversion. Thus, the greater effect of instruction on possessive determiners points to the influence of form/meaning mappings on the effectiveness of explicit form-focused instruction.
