When the perfective ‘le’ operates on an Achievement or Accomplishment, its viewpoint spans the initial and end points of the situation, so it expresses the aspectual meaning of completion, but when ‘le’ operates on an Activity, it also presents the situation as complete. However, since an Activity does not have an inherent endpoint, ‘le’ adds an arbitrary endpoint to the durative activity, making it bounded, thus the aspectual meaning is not completion, but termination (Smith, 1991). Tobin holds that the opposed notion of Result and Process, as a fundamental semantic distinctive feature, cuts across almost all the categories of lexicon and grammar. And indeed, the empirical data shows that the dichotomous distinction between result and process can be found in lexicon, syntax and grammar of the Chinese language.
 Loar, J. K. (2011). Chinese syntactic grammar: functional and conceptual principles. New York: Peter Lang.