In the third episode of Retracing Old Sounds, Dr. Nguyễn Thị Phương Trâm speaks with Associate Professor Dr. Xian Manxue about her work Historical Stratification of Sino-Root Elements in Vietnamese—a study that demonstrates how the familiar layer of Sino-Vietnamese readings represents only one part of the long and complex history of contact between Vietnamese and Chinese. The research reveals that beneath the Tang-period standardized Sino-Vietnamese layer lie much older strata of vocabulary, borrowed across multiple historical stages.

Born in Guangxi, Associate Professor Xian Manxue came to Vietnamese first as a learner and later as a dedicated researcher. She has spent many years reconstructing phonological and semantic correspondences to trace the origins of the various Sino-root layers in Vietnamese. Through this process, she shows how centuries of linguistic interaction have left multilayered traces in the modern Vietnamese lexicon.

Professor Xian Manxue emphasizes that Sino-root vocabulary includes not only the Sino-Vietnamese layer—words such as văn chương (literature), xã hội (society), giáo dục (education)—but also many words that appear “native” to Vietnamese, such as bay (to fly), buồn (sad), buông (to release), buồng (room), gươm (sword), gương (mirror), ghi (to write down), gần (near). Under historical phonological comparison, these turn out to belong to very early layers of borrowing, sometimes far older than the Sino-Vietnamese layer that emerged around the eighth century. For this reason, she proposes the broader concept of “Sino-root elements,” referring to all monosyllabic words with stable phonological–semantic correspondences to Chinese, regardless of their period of borrowing.

In her approach, each Sino-root element is like a “sound fossil,” preserving traces of the phonology at the time it entered Vietnamese. Based on correspondences in initials, rhymes, and tones, nearly 4,000 Sino-root elements in Vietnamese can be grouped into four major strata: Old Chinese (Qin–Han), Early Middle Chinese (late Eastern Han to early Tang), Late Middle Chinese (mid-Tang to Five Dynasties), and Early Modern (from the 10th century onward).

Familiar synonym pairs such as buồn – phiền (sad), buông – phóng (to release), buồng – phòng (room), and bay – phi (to fly) show that Vietnamese, alongside the later Sino-Vietnamese readings, has preserved an older b- initial—the way these words were pronounced in Chinese before the Tang-period shift to ph/f. Similarly, pairs such as gươm – kiếm (sword), gương – kính (mirror), ghi – ký (to write/record), and gần – cận (near) are not cases of “Vietnamized Sino-Vietnamese,” but remnants of older layers of borrowing that preserve pre-Tang consonants.

The multilayered nature of Sino–Vietnamese contact also appears in lexical sets such as the Heavenly Stems and Earthly Branches (tí, dần, thìn, ngọ…), color terms (vàng, tía, xanh—with xanh preserving the ancient meaning of 青), and later borrowings from Southern Chinese speech varieties (hủ tiếu, xá xíu, quẩy, xì dầu), reflecting diverse dimensions of cultural and linguistic exchange.

According to Professor Xian Manxue, identifying the historical strata of Sino-root elements helps us better understand the history of Vietnamese, grasp the principles of vocabulary formation and change, and support more systematic teaching of both Vietnamese and Chinese. More importantly, each Sino-root element serves as a piece of historical evidence, enriching and corroborating studies of cultural and linguistic interactions across the region.