本文研究國語回應標記「是哦」及「哦」在即時通上的言談功能。
兩者均用來回應訊息告知，並且反映談話者認知狀態的改變。另一方
面，談話者所要表達的語意，與上下語境息息相關。兩個回應標記的
主要功能如下：第一、兩者都引出敘述句。不同的是，「是哦」所回應
的是新訊息，而「哦」則可回應新舊兩種訊息。第二、兩者都可被使
用成為所在話輪的唯一成份，暗示談話者有意結束進行中的話題。第
三、兩者都可直接在其後引出新話題。第四、兩者都可引出問句，以
詢問與目前話題相關的訊息。此外，「是哦」可出現在隱含負面語意的
語句之前，以緩和談話語氣。雖上述功能的語境類似，總體而言，「是
哦」語氣較「哦」緩和而禮貌。另外，除了第二、三類的用法表示談
話者有意結束進行中的話題之外，第一、四類的語境也時常暗示談話
者對話題的負面態度。兩者各類功能的分佈情形顯示，「哦」是即時通
上常出現的暗示疏離態度的回應標詞；而「是哦」則是一個較緩和的
回應標記，用來表達「小驚訝」，並經常用來暗示談話者疏離的態度。

This paper explores the functions of the Mandarin Chinese response tokens (RT)
shi-o and o in MSN on-line talk. Both are produced in response to an informing and
betoken a change of cognitive state. Furthermore, the sequential environment of these
two RTs is highly correlated with one’s intended meanings. First, both shi-o and o
occur with a statement in response to an informing. However, shi-o invariably responds
to new information, whereas o responds to both new and given information. Second,
both occur as a free-standing item and suggest disaffiliation or topic curtailment. Third,
both act as a marker of transition to a new topic. Fourth, both RTs introduce a question
to probe for more information. Additionally, shi-o may be used before a dispreferred
response to mitigate the dispreferred second. Whereas the free-standing and
transition-marking RTs signal topic disalignment, the conversational moves of
statement and question attached to these two RTs are also frequently associated with a
negative prosody. In general, o figures in MSN as a strongly dissociative response
particle, whereas shi-o, with a mitigating final particle, is a moderately dispreferred RT
in MSN for indexing of “small surprise”.