Complex sentence: The 1981 ABN World Tennis Tournament was a tennis tournament played on indoor carpet courts at the Ahoy Rotterdam in Rotterdam in the Netherlands that was part of the 1981 Volvo Grand Prix circuit.
Split into simpler sentences: The 1981 ABN World Tennis Tournament was a tennis tournament played on indoor carpet courts at Ahoy Rotterdam in the Netherlands. It was part of the 1981 Volvo Grand Prix circuit.