The purpose of this study is to compare how scores on reading comprehension tasks are affected by switching between two activities within and between languages. Two overarching scenarios with three subsections are involved in this study. The first scenario measures reading task scores when both the reading task and an extraneous task are being performed in one’s second language (L2); the participants switch between tasks but remain in L2. The second scenario measures reading task scores when the reading task is performed in L2, but the extraneous task is performed in one’s native language (L1); the participants not only switch between tasks, but also switch between L2 and L1. The subsections denote the nature of the extraneous tasks: hearing a conversation in the background, speaking with someone face to face, and engaging in text messaging. This study was conducted at the English preparatory school of an English-medium university in Ankara, Turkey. Seven groups of participants completed the same reading comprehension tasks in L2 under varying conditions: hearing a conversation in L2 in the background, hearing a conversation in L1 in the background, engaging in conversation in L2, engaging in conversation in L1, engaging in text messaging in L2, engaging in text messaging in L1, and no distractions. The results indicate that participants scored higher, on average, when remaining in L2 for both tasks and scored lower when switching between L2 and L1. To gain insight into these results, interviews were conducted with two individuals who had engaged participants in conversation and text messaging in L1 and L2. Analysis of the interview transcripts indicates that the word choices and styles of communication differed between L1 and L2, and that participant responses tended to be more extensive in L1, particularly while text messaging. As the findings of this study indicate that overhearing conversation in L1 can pose a distraction to learners working in L2, teachers and students alike ought to be mindful of this and curb the dispensable use of L1 in the classroom. Further pedagogical implications include creating language courses that promote metacognition and reflection in order to raise learner awareness of the effects of task switching, language switching, and divided attention on learning.