This paper probes the semantic development and grammaticalization of yi 以. From the pre-Qin period yi has been involved in multiple semantic values and grammatical functions. Yi is a frequent word in the early texts, but it is not always easy to grasp all the connections among the derivative meanings. Investigation on the semantic development of yi will a) benefit the understanding of diachronic change of the Chinese language, b) provide a model for Chinese historical semantics, and c) aid in the precise understanding of the texts.
The present paper argues that the original meaning of yi is `to take up something with the hand`. The diverse semantic values such as `to reach at hand`, `to arrive`, `to accompany`, `to lead or guide`, `to carry along`, `to use (instrument)` were derived from the original meaning and the meanings `to rely on`, `to be based on` were derived from `to use`. On the basis of the derived semantemes, yi has grammaticalized into function words such as adpositions, pronouns, and conjunctions. When yi is used adpositionally it can indicate means or method of doing something as well as reason or basis, and it also can restrict the range (time, target, and direction) of predicate. Used as pronouns yi not only can serve as demonstrative pronoun `this` but also can serve as interrogative pronouns `what` and `where`. As a conjunction yi can be used to link cause and effect, method and purpose, modifier and modified, and the parallels.
Besides the semantic grounds, the syntactic structure in which yi is used also decisively affected the development. When the verb yi frequently occurs with another verb and form a serial verb construction, the syntactic structure of this kind yields the condition for development into an adposition.
The pronominal usage probably has been grammaticalized from the nominalized yi which indicates reliable objects. The nominalized yi itself has the function of summarizing concrete features in one word, which is similar to the function of pronouns. Furthermore yi has developed into interrogative pronoun just as other pronouns of Chinese.
The usage of connecting cause and effect comes from the adpositional usage of marking reason; linking method and purpose has been grammaticalized from the adpositional usage of indicating method. In the process of the semantic change, the omission of object zhi 之 in relation to the adposition yi played a central role. Connecting modifier and modified is a result of the change from the conjunction yi that connects method and purpose. The usages of conjunction and parallel juxtaposition are basically related to the meaning `to accompany`. Moreover the present paper considers the parallelism between the semantic development of yi and that of ji 及 which is perhaps from the meaning `to arrive`.