Introduction

In evaluating which modern Slavic language a 6-10th century AD Slavic person would find easiest to understand, it is crucial to consider the significant changes that have occurred over the centuries. Modern Slavic languages, while sharing a common ancestral proto-language, Proto-Slavic, have diverged substantially. These divergences can be seen in linguistic features such as vowel systems, intonations, accentuation, and morphology.

The Open Syllable Law and Vowel Systems

Proto-Slavic featured 11 vowels, a complex system that allowed for certain linguistic processes, including the open syllable law. According to this law, every syllable was required to end in a vowel. This constraint was fully effective until the 10th century. In contrast, modern Slavic languages have significantly simplified their vowel systems, reducing the number of vowel types to between 5 and 6. Polish retains nasal vowels, but even this feature exhibits significant variation and blending, making the original distinction difficult to discern.

Prosodic Changes: Accent and Intonation

Linguistic evolution did not stop at vowel systems. The Prosodic structure of Proto-Slavic was markedly different from that of modern Slavic languages. Proto-Slavic had a movable accent, long and short vowels, and two distinct intonations: acute and circumflex. Modern Czech and Slovak retained the length distinction but abandoned the circumflex accent, fixing the accent on the first syllable of a word. In contrast, Serbo-Croatian has a more complex system of four intonations and redefined accent placement. Russian, while often claimed to maintain the correct placement of accent, has also eliminated vowel lengths and the circumflex, resulting in a significant shift in prosodic characteristics. Bulgarian and Russian have shifted to stress timing, a change that has led to the reduction of unstressed vowels. This shift renders Russian nearly unintelligible without prior exposure to the language.

Morphological Innovations and Challenges

Morphology, a crucial aspect of language, also underwent substantial changes. Proto-Slavic had a robust system with noun cases, verb conjugations, and gender distinctions that have been simplified or altered in various modern Slavic languages. These changes have rendered sentences much more difficult to understand, especially for those familiar with the ancient system. Polish and Russian serve as prime examples: Polish has preserved nasal vowels but has mixed them to an extent that it is challenging to identify the original nasalized vowels. Similarly, Russian has simplified its vowel sounds, making it highly unintelligible without prior exposure.

Church-Slavonic: A Potential Role Player

One of the few languages that retains closer ties to Proto-Slavic is Church-Slavonic. This language is an artificial construct based largely on Old Bulgarian with 13th-century Russian phonetics. It is employed in limited parts of the Slavic Orthodox liturgy. However, while Church-Slavonic can provide insight into the morphology and syntax of Proto-Slavic, it is not a natural language and thus not an accurate representation of the spoken languages of the 6-10th century AD.

In conclusion, a person from the 6-10th century AD would likely find it extremely challenging to understand any modern Slavic language. The changes in vowel systems, prosody, and morphology have rendered contemporary Slavic languages nearly incomprehensible without substantial prior exposure and context. Church-Slavonic offers some clues but is not a viable option for understanding the spoken language of the period.