agenda: singular, plural, and agreement
Whether agenda is one list or many items, and which verb it takes.
In current English, agenda is a singular noun meaning a list of things to be done, or a program of aims. It takes a singular verb: The agenda is short. The ordinary plural is agendas. Do not treat agenda as a plural of agendum.
Examples
Use The agenda is on the table.
Use The two committees circulated different agendas.
Avoid The agenda are on the table.
Agendum and agenda as a Latin plural survive in a few formal minutes. They are not the default.