许多年长的居民仍在使用当地方言。

Many older residents still use the local ___dialect.

他说话带着浓重的南方口音，很难听懂。

He spoke with a thick southern ___dialect that was hard to understand.

语言学家研究地区方言以理解语言演化。

Linguists study regional ___dialects to understand language evolution.