The pronunciation of the borrowed Chinese characters in Japanese, Korean, and Vietnamese also provide valuable insights. Old Chinese was not wholly uninflected. It possessed a rich sound system in which aspiration or rough breathing differentiated the consonants, but probably was still without tones.
The Japanese, Korean, and Vietnamese pronunciation of borrowed Chinese characters offers significant insights. Ancient Chinese was not entirely uninflected. It had a diverse sound system where aspiration or rough breathing distinguished consonants, though it likely lacked tones.