A study of the formation of time adverbs Zai and Zhengzai

This study argues that the functions of the time adverb zai can express action progression and state continuance. These two functions stem from different sources. Zai, functioning as state continuance, involves the evolution of {locative verb > time adverb}. This was formed by inducing a metaphor mechanism in the static context. Zai, which performs action progression, evolved from {locative verb > locative preposition > time adverb}. This happened in the dynamic context where serial verb constructions carried out semantic devaluation and the void reference of {zai + demonstrative pronoun} caused the dropping of the locative phrases. The two evolution routes take on typological meaning and are confirmed via cross-linguistic comparison. The time adverb zhengzai was formed in the cause-effect context where the sequence {"zheng "_adverb + "zai + VP"_{verb-object/preposition-object}} cannot be explained by {zheng + zai + VP + zhishi}. The "VP" was then turned into the focus of action events, which led to a reanalysis as {"zhengzai _adverb+ "VP"_{verb phrase}}.