The present study was an attempt to provide a psycholinguistic account of cognitive processes underlying responding and questioning. It also strived to identify the potential differences between responding and questioning cognitive processes in Target Language Use Situation tasks. To accomplish the objectives, 65 Iranian general IELTS applicants from two foreign language learning institutes in Shiraz, with two different language proficiency levels (intermediate and advanced), were randomly selected. They were administered a normal responding and a reverse questioning IELTS oral tasks. Two seven-point Likert scale questionnaires were also used to measure the task difficulty and mental effort that the applicants perceived while doing the tasks. Additionally, the applicants’ recorded voices in tasks were transcribed and analyzed to assess the number of grammatical errors and pause lengths. The analysis of the numerical data through descriptive statistics and paired-samples t-tests indicated that, in general, the cognitive processes underlying oral responding and questioning are significantly different in terms of mental effort, task difficulty, length of pauses, and the number of grammatical errors. More specifically, the results suggested that the applicants took more mental effort and perceived more task difficulty while constructing the questions for given responses irrespective of their proficiency levels. Both groups also paused significantly longer and committed significantly more grammatical errors when completing the questioning tasks. The paper discusses the study implications for second language teachers and assessors.
