hayan cantado
Antepresente de subjuntivo para el sujetoellos/ellas/ustedesdel verbocantar.

cantar

Ninguno de ellos hubiera podido escribir la Marsellesa, suponiendo que no estuviera ya escrita, y es poco probable que hayan cantado con entusiasmo sus estrofas contra los tiranos.
There was hardly one among them who could have written the Marseillaise, even if it had never been written before. It is to be doubted whether they sang the strophes against tyrants with enthusiasm.
Palabra del día
la canela