Language is a system of verbal elements that makes communication of meanings possible in the manners the users intend by employing certain linguistic devices which are partly language-specific. Once communicating cross-linguistically, there is always a risk of negative transfer of techniques or processes from the first language (L1) to the foreign language (L2). The current study investigates the “emphasis” issue and how it is encoded and performed as a speech act in Persian and English. The investigation, based on a descriptive method, begins by verifying overstated and understated utterances in English and Persian individually and then proceeds to evaluate the 2 bodies of data against each other. As observed in the case of Iranian learners of English, the process of emphasizing through phonological devices is heavily transferred. English mainly applies lexicalization, whereas vocalization is the preferred process in Persian. The tenets of this study may be of insight for theories of SLA. They also promise to ease English learning tasks by reducing students' negative transfer from their mother tongue.