The biggest feature of Tongtai dialect is that the ancient voiced initials are pronounced with aspirated and unvoiced sounds, such as "di" thi and "beer" phi. According to this feature, Tongtai dialect can be divided into Huaiyang dialect (the main dialect of Jianghuai Mandarin, namely Hong Chao dialect) and Wu dialect. Because both Gan dialect and Hakka dialect are "full of turbidity", the southern mainland put forward the homology hypothesis of Tongtai Hakka dialect, arguing that Tongtai dialect, like Gan dialect and Hakka dialect, was originated by northern immigrants after Yongjia Rebellion in the late Western Jin Dynasty.

Tongtai dialect has six to seven tones. Compared with Huaiyang dialect with only five tones (Yin Ping, Yangping, Yinshang, Yinqu and Yinqu), there are more Yang Qu (and Yang Qu). The ancient voiced characters enter the present Yang tone, and the ancient full voiced characters are up and down in the present Yang tone in the seventh tone area, but they are classified as flat tones in the sixth tone area as a whole. Being able to distinguish between Yin and Yang and Yin and Yang entering is also a feature that distinguishes Tongtai dialect from Huaiyang dialect.

There is only one main vowel of the ancient pseudonyms in Tongtai dialect, namely "a". But the adjacent Huaiyang dialect and Wu dialect have been separated. Wu dialect generally has two vowels, namely "-o" and "-a", and Huaiyang dialect also has two vowels, namely "-a" and "-iI".

Most points in Tongtai dialect are rich in branching fish, such as "push" and "thunder" pronounced "ly". This phenomenon is not found in Huaiyang dialect, although there are Wu dialects, but the number is far less than Tongtai dialect.

Tongtai dialect is divided into three types, which are roughly the same as Wu dialect and Gan dialect, but different from Huaiyang dialect in the west. Roughly speaking, it is to combine the consonants, vowels and rhyme feet of salty rhyme, but they are different from the tongue and teeth. Similarly, the consonants, vowels and rhyme feet of Shan She's cold rhyme belong to the same category, but they are different from the tongue sounds and consonants of cold rhyme. On this basis, Lu solved his own "Yan Zhitui mystery".

In terms of tone, the tone of Tongtai dialect has disappeared. The yin level is generally lower than the yang level, and the yin entry at all points is lower than the yang entry except Rudong. However, when the positive tone is followed by nasal, lateral, voiced fricative and zero initial, the tone value is lower than the negative tone, such as poison, twelfth lunar month, acquaintance and fifteen.

Tongtai dialect area is located in Jianghuai Mandarin area, which has long been under the jurisdiction of Yangzhou government, and its customs and habits are greatly influenced by Huaiyang culture. Coupled with the country's vigorous promotion and popularization after the founding of the People's Republic of China, Tongtai dialect is close to Huaiyang dialect and Mandarin as the national language. Specifically, it is a group of words that produce a phonetic sound similar to the pronunciation of Huaiyang dialect, and in the long-term existence and competition with the original white tone, the status gradually changes from weak to excellent until it finally replaces the original white tone. For example, the most striking feature that Tongtai dialect differs from Huaiyang dialect is that the initials of voiced consonants are voiced fricative, voiced stuffed and aspirated. In the written pronunciation, the intonation is not aspirated and unvoiced, which is consistent with Huaiyang dialect and the whole northern dialect. Generally speaking, Tongtai dialect produces more literary readers in the west than in the east.