Here's a breakdown:
* Old Chinese: The character 犬 (pronounced "quǎn" in modern Mandarin) was used to represent the dog.
* Old Japanese: The character 犬 was adopted into Japanese, and it was pronounced "inu".
* Evolution: Over time, the pronunciation of the character in both Chinese and Japanese changed. The modern Mandarin pronunciation "quǎn" is different from the old pronunciation, and the Japanese pronunciation "inu" remained relatively stable.
Therefore, the word "inu" is ultimately derived from the Chinese character 犬. It was borrowed into Japanese and retained its meaning and pronunciation, although the pronunciation of the character changed in both languages.
This is a common occurrence in Japanese, as the language borrowed a significant number of characters and words from Chinese during its development.