This study investigates the efficacy of various grammar instruction techniques, namely focus-on-form (FonF) and focus-on-forms (FonFs), on the acquisition and production of the English passive voice. A quasi-experimental pre-test and post-test design was employed across four treatment groups without a control group, involving 62 Turkish learners of English, enrolled in preparatory classes at a public university in Turkey, with a B1 (intermediate) proficiency level. The study assessed the effectiveness of input flood (IF), input flood coupled with textual enhancement (IF + TE), input flood with explicit grammar teaching (IF + EGT), and rule-based instruction (RBI). Authentic texts on global warming and climate change were used as materials, with passive sentences underlined for the IF + TE group and explicit grammar explanations provided to the IF + EGT group. Findings point to a clear superiority of RBI in the learners’ grammatical acquisition and production, supporting the idea that explicit instruction, followed by controlled practice, significantly enhances learning outcomes. Contrary to RBI's success, the IF only approach did not yield a substantial impact, questioning the effectiveness of implicit teaching methods for complex grammatical structures. The study also examined the relationship between explicit knowledge and communicative practice, finding that explicit instruction is critical even within communicative frameworks. These outcomes align with the Noticing Hypothesis, emphasizing that conscious recognition of grammatical forms is necessary for effective language acquisition. The study contributes to the ongoing debate on the efficacy of explicit grammar instruction versus implicit learning, suggesting that a combination of instruction focusing on form within a communicative context can be beneficial for EFL learners.