Complex sentence: The United States dollar (sign: $; code: USD; also abbreviated US $), also referred to as the U.S. dollar or American dollar, is the official currency of the United States and its overseas territories.
Split into simpler sentences: The United States dollar (sign: $; code: USD; also abbreviated US $), is referred to as the U.S. dollar or American dollar. It is the official currency of the United States and its overseas territories.