西周金文中的「叚」出現的位置、辭例經常與「敢」字相同，故「叚」與「敢」是否代表同一詞是頗受學者關注的問題。其實西周金文中，「叚」也不乏從不與「敢」混用的辭例，二者基本上是有差異的。因「叚」、「敢」都出現在君臣對話的情境中，故本文擬從君臣身份差異的觀點切入，探討二者在使用上的差異。此外，《詩經》中頗多從「叚」聲的詞彙，包括以「遐」為主的「不遐～」、「遐不～」，以及以「瑕」為主的「不瑕～」等，它們雖然都用於祝福，但從它們所接的詞彙觀察，「遐不～」只接正面語而「不遐～」只接負面語，則「遐不～」、與「不遐～」的意涵是不同的。至於「不瑕～」在《詩經》中用來表示意願的強烈，和「遐不～」、「不遐～」用於祝福，同樣也是不同的。

That ＂jia＂(叚) and gan(敢) always appear in the same words and phrases in Western Zhou bronze inscriptions draws scholars' attention to study whether the two words carry the same meaning. Many Western Zhou bronze inscription examples show that the two words are never used alternately and thus imply that they carry different meanings. Since both ＂jia＂ and ＂gan＂ exist in various dialogues between kings and their ministers, this article focuses on identity differences to investigate their usage differences. Further examined are three words that contain characters rhymed with ＂jia＂ in the ＂Classic of Poetry＂: ＂bu-xia＂(不遐), ＂xia-bu＂(遐不), and ＂bu-xia＂(不瑕). ＂Bu-xia＂(不遐) and ＂xia-bu＂(遐不) are both used for good wishes, but the former is only followed by negative phrases and the latter only by affirmative ones. Totally distinct from these two words, ＂bu-xia＂(不瑕) is used to express a strong will.