Why can speakers of different Chinese languages have trouble understanding one another?

Speakers of different Chinese languages often struggle to understand one another because these spoken varieties are mutually unintelligible. While they are frequently referred to as dialects, scholars generally classify them as separate languages because they differ from each other to a degree comparable to the modern Romance languages.1

The primary barriers to mutual intelligibility are differences in pronunciation and vocabulary, though the grammatical structures remain largely similar. A significant factor in these phonetic differences is the use of tones to distinguish word meanings; for example, Modern Standard Chinese utilizes four tones, whereas more archaic varieties like Cantonese use at least six.1

Although these languages share a common literary tradition written in characters, this system lacks a single standard of pronunciation. Consequently, speakers read texts according to the phonetic rules of their own specific language. To address these communication challenges, Modern Standard Chinese—based on the Beijing dialect—was developed as a national standard to unify communication across diverse linguistic regions.12