Since the early 1990s, the body of literature on second language (L2) composition instruction has been profoundly influenced by corpus linguistics research, which empirically demonstrated the recurrence of formulaic sequences—defined as highly frequent register-, genre-, and/or discipline-bound multiword strings (Hyland, 2008a; Simpson-Vlach & Ellis, 2010)—in academic writing. These findings led several researchers to advocate the importance of integrating formulaic sequences into L2 writing pedagogy and the effectiveness of focused instruction, salient input, and repeated exposure in promoting their acquisition and improving L2 learners' writing proficiency (e.g. Cowie, 1992; Lewis, 1997; Willis, 2003; Wood, 2009, 2015).

The growing theoretical accounts of the importance of integrating formulaic sequences into L2 composition instruction has been associated with very few research studies on formulaic sequences and L2 learners' academic writing skills, most of which focused on one pedagogical approach and yielded inconsistent results. Accordingly, there is, as yet, no ample evidence to support the effectiveness of formulaic sequences in improving L2 learners' academic writing skills; nor is their sufficient evidence to demonstrate the pedagogical efficacy of the above-mentioned approaches.

To address these gaps, this quasi-experimental research study investigated the extent to which focused instruction and salient input can help English for Academic Purposes (EAP) students acquire and manipulate formulaic sequences to produce better quality graphical summaries and essays. The study was conducted in an EAP program, different pedagogical interventions were delivered, and 382 timed written texts were collected at three time points from 67 upper-intermediate and advanced students. The textual data were manually quantified, statistically analyzed, and blindly evaluated. The study results were generally in agreement with the literature on the effectiveness of focused instruction and salient input but at odds with the literature on the positive effects of formulaic sequences on L2 academic achievement. The results also highlighted the higher learning gains that a focused instructional approach resulted in than a saliency approach and revealed the effects of the writing task and proficiency level on the participants' utilization of formulaic sequences. These results formed the basis for suggesting implications for EAP contexts and highlighting yet-to-explore areas for future research.