Variation in language use can be approached from two dimensions: one is user-related varieties which are called dialects and the other is use-related varieties which are called registers.
语言变体可以分为两类：一是与使用者相关的语言变体—方言，另一类是与使用相关的语言变体—语域。
2
Like a family tree that you might use to trace back through generations of ancestors, only it's showing a family of genetically related languages instead of people.
就像你可以追溯祖先的家谱一样，它只是在显示与遗传相关的语言，而不是人类。
3
The third factor related to the popular use of English is the boom in international travel.