What other aspects of culture might link people in a country who speak
different languages?

People in many countries all over the world speak different languages, come from different cultures, like the United States, for example. Although English is the most spoken language, people also speak Spanish, German, Dutch, Chinese, French, and others. But under one nation, we come together during some hard times. Rebuilding after hurricanes, firefighters going into fires to save lives, police officers risking their lives to make our country safe, there are a whole lot more examples. People everywhere come together to help one another, or other purposes, like churches, companies, and recreational purposes for example.

associative property of addition