This is the 1938th most frequent Spanish word.
registradas
"Registradas" means "registered" in English.
Here, 'registradas' is used as a past participle of 'registrar', meaning 'recorded' or 'entered'. It acts as an adjective modifying 'actividades'.
Las actividades fueron registradas en el sistema.
The activities were recorded in the system.
In this instance, 'registradas' is the past participle of 'registrar', referring to people who have completed the registration process. It functions as an adjective.
Las personas registradas para el evento recibirán información adicional.
The people registered for the event will receive additional information.
'Registradas' is part of the verb phrase 'se han registrado', meaning 'have been registered'. It points to the act of recording complaints.