1800 in English is pronounced as "eighteen hundred." It comes from the fact that 1800 is the number 18 followed by two zeros, which represent the hundreds place in a number. Here are some example sentences using 1800 in English:

The 1800s were a time of great change and progress in many parts of the world.

The 1800s saw the rise of the Industrial Revolution, which brought about many technological advancements.

In 1800, the United States had a population of about 5 million people.

The 1800s were also a time of great exploration and discovery, with many famous explorers setting out to chart new territories.