Socioculturally oriented developmental Interlanguage Pragmatics (ILP) studies have just recently drawn the Second Language Acquisition (SLA) researchers' attention, and the role of concepts like peer scaffolding, and the Zone of Proximal Development (ZPD) in ILP development are among rich areas in need of attention. The present study investigates the significance of the effect of expert peers' ZPDwise, co-equal peers' ZPD-insensitive and teacher fronted ZPD-insensitive scaffolding on EFL learners' pragmatic development. The number of students who participated in this study was 85 of which 27 were male and the rest were female. They were organized into three experimental and one control groups. The subjects in the experimental groups were given either explicit ZPD-wise or implicit ZPD- wise scaffolding by the expert peers, or ZPD-insensitive scaffolding by their coequals, while the subjects of the control group received ZPD-insensitive teacher scaffolding. The study reveals that the expert peers' ZPD-wise explicit and implicit scaffolding are more effective than the other two intervention types for the ILP development, however, the co-equals' scaffolding proved to be the third effective procedure for the subjects' co-construction of ZPD and ILP development. An implication of the study is that different forms of peer scaffolding are relatively effective for the EFL learners' ILP development.
