The last two decades have witnessed many studies reporting factors that promote second language (L2) learners' pragmatic competence such as pragmatic input, language proficiency, and pragmatic instruction. Length of formal study, although it may relate to language proficiency indirectly, has been a rather neglected aspect in pragmatic acquisition research. This study analyses the effects of length of time spent learning English formally on English language learners' ability to evaluate impoliteness and the foundations by which they evaluate it. Empirical data were collected by means of questionnaires and a semi-structured interview from one hundred EFL teacher trainees at a private university in Central Java Indonesia. The participants were divided into two groups. Group 1 (n = 50) studied English for nine and half years and group 2 (n = 50) studied English for eight and half years. The overall results revealed that the length of time spent learning English affected the learners' capability of comprehending impoliteness in particular off-record impoliteness. The English learners in the present study mostly used Quality face violation as the foundation of impoliteness evaluation.