The phrase "一动不动" (yī dòng bù dòng) is formed through a fixed and emphatic grammatical pattern in Chinese, where the structure "一 + Verb + 不 + Verb" is used to denote the absolute negation or absence of an action. Here, the verb "动" (dòng), meaning "to move," is placed after "一" (yī, "one") and then repeated after the negator "不" (bù, "not"). This creates a literal reading of "not even one move," implying complete stillness or total lack of motion. The reduplication of the verb within this framework intensifies the meaning, resulting in an idiomatic expression that vividly describes a state of being perfectly motionless or frozen.