When someone sneezes, in some countries, people say "God bless you." Nobody really knows the start of this response, but people have several theories about it.

In the past, when someone sneezed, people thought that his soul left the body. All they could saw was "God bless you."

In the 6 th century, a plague happened in Europe, and Pope Gregory I ordered people to give blessings to someone who sneezed. In the 14 th century, another plague happened, and a person who sneezed could be sick. People started to say, "God bless you."

These days, for many people, the response is a natural reaction, and many think that it is polite to say it. In some countries, people don't say it. For example, in Spanish language countries, people say the word "salud." It means something like "good health".

Difficult words: theory (a set of ideas to explain something), plague (a dangerous disease which spreads quickly and kills many people), blessing (God's help).