Watching an American TV series, I found that there are a lot of common expressions in people's conversation. Reactions, phrases, actions...etc.   My husband who is American, also uses those aformentioned, common expressions. Likewise, I probably use expressions similar to a lot of Japanese people's. I think that our behavior is influenced/informed by what we've experienced. Learning those conversation patterns might help one to acquire a language. 

You bring up a very good point! It seems that every culture and by extension, every language has its own quirks that make them unique!