從六朝開始，漢語史上便陸續出現標誌充分條件的連詞，包含單音連詞「但」以及
雙音連詞「但使」、「但令」、「但是」、「但凡」、「只要」等。這些連詞或源自限定副詞，
或由限定副詞所構成，顯示限定副詞和充分條件連詞具有一定的演變關係。本文希望能
釐清其闊的演變，包括從副詞到連詞的語法化演變以及雙音連謂的成詞演變。文中指出，
限定副詞「但」和動詞組「只要J '是因為吸納語境中的關係義市語法化為充分條件連詞，
「但使J 、「但令」和「但是」則是由於動詞「使」、「令」和「是j 語法化後粘附於前方的
連詞「但」而形成，並列式連詞門旦凡J 則是依詞法權合而成。若根據構成關係，這五
個雙音連詞可分成三種:組合式、偏義式及並列式。漢語史上雖然陸續出現標誌充分條
件的連詞，且其使用頻率也日漸提高，但它們並非此顯句式的必要成分，只起強化或鞏
固關係的作用。

Since the Six Dynasties, a number of sufficient conditional conjunctionshave developed, inc1uding the monosyllabic conjunction dan and the disyllabicconjunctions danshi (但使)， danling, danshi (但是)， danj仰， and zhiyao.All of these conjunctions were derived from or composed of restrictiveadverbs, indicating that there is an evolutional relationship between therestrictive adverbs and the sufficient conditional conjunctions. This paperdiscusses the grammaticalization of these sufficient conditional conjunctionsand also the formation of the five disyllabic conjunctions. The paper arguesthat (a) it was due to the absorption of the contextual meaning that therestrictive adverb zhi and the verb phrase zhiyao were grammaticalized intosufficient conditional conjunctions; (b) the formation of the disyllabic conjunctionsdanshi (但使)，卻nling， and danshi (但是) was initiated by thegrammaticalization of shi (使)， ling, and shi (是)， respectively; and (c) thecoordinating conjunction danfan was formed through compounding. Theconstruction of the five disyllabic conjunctions can be grouped into threetypes: compositional ， ρianyi (which takes the meaning of just one of the twomorphemes), and coordinative.