在zai and着zhe are commonly recognized imperfective aspect makers in Mandarin Chinese, though there are noticeable differences between their distributions and functions. By resorting to origins, historical evolutions, and corpus data for the meanings and functions of these two characters, it can be observed that they are both polysemies displaying semantic networks organized around a central sense respectively and the characters 在 and 着 are distinct form and meaning pairings. 在 is a construction indicating presence within a certain range while 着generally denotes ‘reach to’. Related to their basic meanings, 在 and 着 exhibit some constraints respectively when marking imperfective aspect. From this character-based constructional account, 在’s and ...