In Korean, sub-clauses and verb phrases are not affected by the tense of the main clause. 자는 척 or 잔 척 just describes the act itself independent of the tense of the sentence. 자는 척 means pretending to sleep at the moment, whereas 잔 척 is pretending to have been sleeping until some recent point in time but not at the moment. 잔 척 is much more rare, and is often said as 잤던 척 to make it more clear. The difference between 자는 척 and 잔 척 is the same one between 내가 하는 일 (the work I do) and 내가 한 일 (the work I have done). The former describes the ongoing present, while the latter refers to a completed thing. Check the tens relations in these examples: - He said he was a student = 그는 자기가 학생이라고 했다. (이라고 = 이다 (present) + -(다/라)고 - unaffected by 했다) - 그는 자기도 학생이었다고 했다 = He said he too had been a student. (이었다고 = 이었다(past) + -고)

present - 자는 척하다 past - 자는 척했다. its like " i do / did action 'sleep' "

Maybe 저는? 아니면 전?

잔 척했다는 과거이고 자는 척하다는 현재예요