This study investigated the effects of processing instruction (PI) on the acquisition of the subjunctive in adjectival clauses by 92 intermediate-level distance learners of Spanish. PI is a novel instructional technique that is based on VanPatten’s principles of input processing (1993, 1996, 2002, 2004), and it has three key components: (a) an explicit explanation of grammar that is not paradigmatic, (b) information on processing strategies, and (c) structured input tasks and activities.

Structured input activities were isolated and combined with computerized visual input enhancement (VIE) in an attempt to increase the salience of targeted grammatical forms for web based delivery. VIE was operationalized as word animation of subjunctive forms through flash programming language.

An experiment comparing four experimental groups with traditional instruction indicates that for interpretation and production tasks, there were no significant differences between PI and traditional instruction. However, learners who received PI combined with VIE outperformed learners who received structured input activities without VIE for interpretation tasks.

In addition, the present study examined the effects of PI when learners encountered targeted forms that were embedded in an authentic input passage that was received following the experimental exposure. Thus far, studies in the PI strand have only examined how learners interact with structured, or manipulated, input. The results of the present study indicate that participants who received PI in combination with VIE noticed targeted forms in subsequent authentic input with metalinguistic awareness, and they demonstrated a significantly higher level of awareness than participants who received traditional instruction or structured input activities. Further, learners who received PI, with or without VIE, were better processors of targeted forms that were embedded in subsequent authentic input than learners who received structured input activities without VIE.