The average English-speaker knows about 25,000 words. And yet those 25,000 words can be combined into an infinite number of sentences -not a simple process. Many people believe that, whatever language you speak, the words you know have a profound influence on the way you think. This is a controversial theory among linguists. In this edition of the Why Factor, Lane Greene explains how paying attention to the language we use can give us a greater understanding of our politics, our debates, our cultures and even our own minds.

(Image: Top of woman's head with the word "hello" written in different languages floating above. Credit: Aysezgicmeli/Shutterstock)