Going somewhere? Emigrate means to leave one's country to live in another. Immigrate is to come into another country to live permanently. Migrate is to move, like birds in the winter.

The choice between emigrate, immigrate, and migrate depends on the sentence's point of view. Emigrate is to immigrate as go is to come. If the sentence is looking at the point of departure, use emigrate. The point of arrival? Immigrate. Talking about the actual process of moving? Use migrate.

Emigrate means you are exiting your current homeland:

People are always saying there's no quality of life in Russia, and everyone wants to emigrate," he said. (New York Times)

Immigrate means you are coming in to a country to live:

Citizens from 17 European Union countries were given freedom to immigrate to Switzerland in 2007. (Business Week)

Migrate means to move, like those crazy Monarch butterflies that migrate from Canada to Mexico and back. It doesn't have to be a permanent move, but migrate is more than a weekend away, and it's not just for butterflies. "Snowbirds" are people who migrate south for the winter and come back north when the snow melts, or someone might migrate to another part of the country for work or to be closer to family. Here are some examples:

Nevertheless, it has often been assumed that dinosaurs did migrate.(Scientific American)

People are prepared to travel and migrate within America. (Business Week)

If you have ants in your pants and you have to move, remember:

Emigrate is from the point of view of the departure. Think exit.

Immigrate is from the point of view of the destination. Think come in.

Migrate is all about the moving. Think move.