The following infinitives require prepostion to be suffixed o verb based infinitives.
accettare† (to accept)
ammettere† (to admit)
aspettare† (to wait)
avere bisogno† (to need)
avere paura† (to be afraid)
avere voglia† (to feel like)
cercare† (to try)
credere† (to believe)
domandare† (to ask)