古今字的古字和今字在读音上是相同或相近的,而其中一类由词义引申派生新词而产生的今字与记录源词的古字在意义上也是相通的,这些特征和同源字的音近义通特征相同,因此,古今字和同源字有着一定的联系,但并不能说古今字就完全属于同源字。只有因词义引申而形成的古今字才是同源字,因词义假借形成的古今字由于意义上无相通之处则不是同源字。 Ancient and modern characters and the ancient word in the pronunciation of the pronunciation is the same or similar, and one of the derivation of new words derived from the meaning of the word and ancient words recorded source words in the same sense, these characteristics and the same Therefore, there is a certain relationship between ancient and modern Chinese characters and cognate words, but it can not be said that ancient and modern Chinese characters belong to the same origin. Only the ancient and modern Chinese characters formed by the extension of the meaning of the words are the same origin words, because the ancient and modern characters formed by the meanings of the word meanings are not homologous words in the sense of no similarity.