Cognomen Twen (Train 
, Twen 
, ยี่สิบ) , in all the world, is quite a common surname. The family name Twen is habitual in the United Kingdom, where it is a rare surname, Australia, and France. Measured by absolute frequency, it is the most numerous in the United States, the United Kingdom, and France. Much less frequently, Twen is the forename as well as the last name.