The main purpose of this project is to improve efficiency.

The water mains burst due to the earthquake.

Maine is known for its beautiful coastline and delicious seafood.

The mains supply water to all the houses in the neighborhood.

We are having fish for our main course.

The water main in our neighborhood burst and caused a major water outage.

The main thrust of the argument was that education is the key to success.

He saw the job offer as his main chance to make a lot of money.

The main clause of the sentence provides the main idea or the main action.

The crew gathered on the main deck to prepare for the storm.