Pragmatic competence is among the explicitly acknowledged sub-competences that make the communicative competence in any language (Bachman & Palmer, 1996; Council of Europe, 2001). Within the notion of pragmatic competence itself, "implicature (implied meanings)" comes to the fore as one of the five main areas there (Levinson, 1983). In this regard, the present study developed an online multiple-choice discourse completion test (MDCT) to specifically measure the interpretation of formulaic, thus teachable implied meanings in English. After the initial version produced with the help of a native speaker colleague, the test was piloted rigorously with different comparison groups. At the end of the process, 112 EFL Teacher Trainees, 33 native speakers of English, 37 EFL learners at a university School of Foreign Languages and 11 high school EFL students had taken the test as the comparison subgroups with varying proficiency levels. Moreover, seven ELT professional native speakers had been interviewed about each test item to have their direct feedback on wording and all the revision/improvement alternatives. Consequently, significant performance differences were detected between particular pairs of subgroups, which is a strength of the test as it did reflect the performance variability between the participants from different proficiency levels. The outcome was a MDCT that the native speaker takers reached a good compromise on and is usable both in computerized and pen-and-paper format, which can be used in any ELT or ELT teacher training program concerned to diagnose the students' performance in a major area of pragmatic competence to later take informed instructional decisions.