The word "不到" is formed through the direct combination of two fundamental characters: 不 (bù), meaning "not", and 到 (dào), meaning "to arrive" or "to reach". Its formation is a purely conceptual and directional negation, where the idea of "arriving" is simply and logically denied, creating the core meaning of "not reaching" a point, whether that point is physical ("the location"), quantitative ("the amount"), or temporal ("the time"). It is a compound built from the negation of an action of attainment.