This paper analyzed the use of the multi-functional word ‘yu(欲)’ used as verb, auxiliary verb, future tense marker, etc., and discussed the path of meaning development and its mechanism.
First, the verb ‘yu(欲)’ in Pre-Chin Period was used in ‘NP1+V欲+NP2’, indicating the meaning of ‘desire’. The verb ‘yu(欲)’ has expanded its function to take the object of complex structures such as abstract nouns, verb phrases, and subject-predicate structures.
Second, when VP of ‘NP+Vyu(欲)+VP’ is [+control], the structure of ‘NP+Vyu(欲)+VP’ is re-analyzed as ‘NP+Auxyu(欲)+VP’. At this time, the verb ‘yu(欲)’ in the meaning of ‘desire’ is changed to ‘volition’ type auxiliary verb.
Third, the verb ‘yu(欲)’ in the meaning of ‘desire’ appears in the topic-comment sentence can infer the ‘necessity’ of VP. These ‘yu(欲)’ develop into auxiliary verbs that represent [necessity] during the period of The Six Dynasties.
Fourth, if the VP of ‘NP+Auxyu(欲)+VP’ is [-control], the [+ intention] feature of ‘yu(欲)’ is suppressed, and the meaning of ‘yu(欲)’ is developed into ‘prediction’ type future tense with [-intention], [+prediction], and ‘schedule’ type future tense with [-intention], [-prediction].