This paper discusses the lexicalization of "suoyi(所以)" from a composition of the noun phrase to a conjunction of result and to a discourse marker. during the grammaticalization of "suoyi(所以)", sematic subjectification has occurred. sematic subjectification of "suoyi(所以)" can operate in three related aspects, which involve meanings from the content domain to the epistemic domain, with extention to the speech act domain, and increasingly based on the speaker`s subjective belief state toward the proposition.
