If you're learning a language, you usually just focus on the standard variety.

如果你正在学习一门语言，你通常只关注标准的多样性。

Almost all languages have standard varieties, the ones that are used by those groups with power, money, and education.

几乎所有的语言都有标准变体，那些有权力、有钱和受过教育的群体使用的变体。

The difference between a standard variety of a language and the nonstandard varieties is not one is better than the other or one is somehow more sophisticated than the other;they're simply different.

一种语言的标准变体和非标准变体之间的区别不是一个比另一个更好，或者一个比另一个更复杂；它们只是不同。

But, by the 19th Century, a standard variety of American English had developed in most of the country, based on the dialect of the Mid-Atlantic states with its characteristic flat " a" and strong final " r" .

但是，到 19 世纪，标准的美国英语变体在该国大部分地区发展起来，其基础是中大西洋各州的方言，其特征是扁平的“a”和强大的词尾“r”。