Question

language change
1 in some ways, it is surprising that languages change. after all, they are passed down through the generations reliably enough for parents and children to communicate with each other. yet linguists find that all living languages change over time—albeit at different rates. for example, while japanese has changed relatively little over a thousand years, english evolved rapidly in just a few centuries. many present - day speakers find shakespeares sixteenth - century plays difficult and chaucers fourteenth - century the canterbury tales nearly impossible to read.
2 languages change for a variety of reasons. large - scale shifts often occur in
what is the main focus of the text?
how and why language changes over time
why the works of shakespeare and chaucer are difficult for modern readers
why different languages evolve at different rates

Explanation:

The text first mentions that languages change over time at different rates (how), and then states that languages change for a variety of reasons (why). References to Shakespeare and Chaucer are examples of language - change over time, and the rate - difference between Japanese and English is also part of the "how" language changes.

Answer:

how and why language changes over time